UNESCO, Bangkok, July 1987

TYPHOON RESISTANT SCHOOL BUILDINGS FOR WET NAM

VIET NAM

Department of Educational Buildings Ministry of Education Educational Facilities Development Service UNESCO K.J. Macks, architect, UNESCO consultant

CONTENTS

,

I. INTRODUCTION

II. FIELD TRIP REPORT

III. EDUCATIONAL BUILDINGS IN THE TYPHOON AFFECTED AREAS OF VIET NAM

1. Typhoons and cyclones in Viet Nam: their damages to educational buildings

2. Measures against typhoon damages 3. Conclusions 4. Comments on report by K.J. Macks

IV. GENERAL PRINCIPLES OF EDUCATIONAL BUILDING DESIGN WHICH HAVE RELEVANCE TO TYPHOON AFFECTED AREAS

V. CONSIDERATIONS FOR THE DESIGN OF TYPHOON RESISTANT BUILDINGS IN VIET NAM

VI. SUMMARY OF CONCLUSIONS

VII. FUTURE ACTIONS UNDER THE PROJECT

APPENDICES ---

1. Summary of opening statement by Ministry of Education 85

2. Summary of opening statement by Unesco 86

3. Itinerary, 87

4. Lists of names 89

A. Key officials contacted B. Persons involved in field trip C. List of participants in workshop and training course

5. Schedule of reports presented at workshop and training course

92

6. Schedule of papers provided by MOE 93

7. Schedule of papers and materials provided by UNESCO 94

8. Summary of workshop discussions 95

9. Summary of training course discussions 108

PaBe

1

9

25

25 41 50 51

53

59

79

83

Participants of the workshop and training course.

I. INTRODUCTION

Viet Nam is one of the Asian and Pacific countries which is frequently battered by cyclonic storms (or typhoons). The annual number of storms averages from three to five and most frequently strike the central and northern part of the country (Figures I-1, 1.2, 1.3). The fifth such storm in 1986 struck two provinces just south of Hanoi and for which the Ministry of Education has given the following statistics of damages.

1,520 classrooms destroyed 12,850 classroom roofs damaged

1,106 laboratories/workshops etc. destroyed 1,473 laboratories/workshops etc. roofs damaged

760 teachers' quarters destroyed 420 teachers' quarters roofs damaged

Following each major storm statistics are collected and appeals, both national and international, are made for assistance to the affected areas. Amongst the international agencies to which Viet Nsm appeals for help is Unesco. Unesco, however, is not an aid giving agency and is in no position to respond to the requests for vast amounts of aid. Based on the official statistics for the 1986 storm, for example, about one square kilometer of school building roofs need to be replaced.

Being aware of this perennial problem, Unesco, Bangkok invited Viet Nam to participate in a training course on educational buildings in cyclone affected areas which took place in Manila in March 1986. The two participants were Mr. Nguyen Dinh Phung of the Ministry of Education and Mr. Le Quany Huy of the State Committee for Constru&ion.

The Ministry of Education has decided that it would like to bring to an end this problem of annual damages and plans to do this in two phases.

Phase I : 1986 - 1987 : Undertake a design study for the development of prototype structures.

Phase II: 1988 onward : Begin implementation of new designs in several selected districts as pilot programmes.

This experience would then be transmitted to other districts for an ever wider scale application.

In response to a request for assistance by the Ministry of Education Unesco has mobilized a limited amount of resources to support a research and development activity on,typhoon resistant school buildings in Viet Nam. These funds have been taken from regular programme sources ($10,000) and from the UNESCO-AGFUND project Development of Educational Facilities in Asia and the Pacific ($14,000).

The first step in this activity has been for Unesco to carry out a mission to Viet Nam to work with Vietnamese technical personnel. Mr. Kevin J. Macks, consultant architect from Australia and Mr. John Beynon,

1

Principal Architect, UNESCO, Bangkok, spent 14 days in the country (15-29 June). The mission was composed of three parts: i) field visits to two Districts in the affected areas, which included Tien Hai District of Thai Binh Province and Xuan Tuay District of Ha'Nam Ninh Province; ii) a workshop to discuss the problems of the various provinces as well as the various solutions proposed by the Ministry of Education, Department of Educational Buildings (DEB): iii) a training course on the theory of building design in cyclone affected areas (Figures 1.4, 1.5).

This report covers the results achieved during the mission.

The next steps will be for the DEB to prepare preliminary designs based on the observations made during the field trip. The suggestions received during the workshop and the technical guidance made through the training course will be followed by the construction and testing of prototype schools in several of the most affected Districts along the coast.

There is every reason to believe that there is a technical answer to the problems. While the resultant designs will rely as much as possible on the use of local materials it is necessary to tie down the various building components with steel fasteners and steel reinforcement. While these are of simple design which can eventually be produced in Viet Nam, the country will require some further external assistance to be able to achieve this. This report, therefore, looks into the need for such assistance.

In view of the need for external assistance and the importance of trying the activities of this project in with those which have been initiated by other agencies or governments contacts were made with UNICEF, UNDP and the Australian Embassy.

As UNICEF is involved in various educational programmes which include the provision of teaching materials, it is necessary to ensure that buildings are secure and provide adequate protection against rain.

UNDP and the government are in the processes of finalizing a project entitled Disaster Preparedness and Rehabilitation. Binh Tri Thien Province which includes three components: improvement of the gathering of meteorolo- gical data, establishment of typhoon proof communication systems and the demonstration of disaster resistant construction techniques for local builders.

With the Australian Embassy discussions centered around the transfer of Australian technology to the conditions in Viet Nam and in particular for the fabrication of galvanized steel cyclone straps for attaching roof members to the structure. The Embassy was informed of Unesco's intention to prepare a project for external assistance which would include, in the first instance the provision of ready made materials, and for the long term the development of industrial capacity to produce these components in Viet Nt3Ill.

Particular thanks are due to the cooperation received from the Government of Viet Nam and in particular H.E. Pham Minh Hat, Minister of Education, Dr. Tran Xuan Nhi, Vice Minister of Education, Mr. Nguyen Chi Linh, Director of External Affairs (MOE) and Mr. Nguyen Dinh Phung, Acting

2

Director, Department of Educational Buildings (MOE).

Chapter V of this report by Mr. Kevin Macks has benefited from contributions by the following persons. Mr. David Lloyd of Blain Bremner and Williams Pty. Ltd., Consulting Engineers has checked the calculations of forces and the theory of physics. Professor George R. Walker of James Cook University and Mr. Greg F. Reardon, Technical Director of the Cyclone Testing Station and Professor Joe Minor of Texas Technical University have advised on the selected wind speeds and wind zones.

H.E. Dr. Pham Minh Hat hosted a dinner for the UNESCO team and discussed at length the work being done under this project. Dr. Tran Xuan Nhi, Vice Minister of Education, personally guided the activities of the full two-weeks and chaired or attended all sessions of the three day workshop. He has instructed those who attended the workshop and training course to implement the recommendations.

3

M * Morn Season AUGUST OCTOBER WESTERN NORTH PACIFIC Man Saxon APRIL DECEMBER

NORTH INDIAN OCEAN EASTERN NORTH PACIFIC

Motn seo,on. JUNE OCTOBER wth ugnlf,cont occurrences

I SOUTH INDIAN OCEAN ” .

Matn Season. DECEMBER MARCH

SOUTHWEST PACIFIC and AUSTRALIAN AREA Maon Seoron: DECEMBER APRIL

Figure I.2 MAP OF VIETNAM

1’: CHINA

THAILAND

GULF

OF TII. 81 1 .I

LAOS

/ II-IAILANIJ

KAMPUCHEA 1

24’

22’

20’

18’

16’

14’

12’

IO’

Is

.- _-.- -. -- __II-_-

Figure I. 3 TRACKS OF CYCLONES 1975-1986

KEY f- Heavy storm f------ Weaker storm

6

Figure I.4 VIETNAM - PROVINCES

* Ha Noi (capital)

1. Lai Chau 2. Son La 3. Hoang Lien

Son 4. Ha Tuyen 5. Cao Bang 6. Lang Son 7. Bat Thai 8. Quang Ninh 9. Ha Bat

10. Vinh Phu 11. Hai Hung 12. Ha Son Binh 13. Hai Phong 14. Thai Binh 15. Ha Nam Ninh 16. Thamh Hoa 17. Nghe Tinh 18. Binh Tri Thie 19. Quang Nam -

Da Nang 20. Nghia Binh 21. Phu Khqh 22. Gia Lai -

Kontum 23. Dac Lac 24. Lam Dong 25. Thuan Hai 26. Dong Nai 27. Song Be 28. Tay Ninh 29. Long An 30. Ho Chi Minh

city 31. Tien Giang 32. Ben Tre 33. Cuu Long 34. Dong Thap 35. Hau Giang 36. An Giang 37. Kien Giang 38. Minh Hai 39. Vung Tau -

Corn Dao

loll’ 102’ 104- 106 * 108.

i

Figure I.5 UNESCO MISSION - JUNE 1987 - PROVINCES VISITED

THAILAND

JI. FIELD TRIP REPORT

Educational Profile

The educational system follows a EG-5-3-3 pattern where the levels include kindergarten, Basic General Education (which covers the five years of primary and three years of lower secondary sections) and upper secondary education. Both provinces visited reported that nearly one person in three attends some kind of educational activity and that they have several primary teacher training institutions. Table 1I.a provides a comparative picture of the two provinces and the two districts which were visited. For the most part kindergartens and upper secondary schools work on single shifts while the Basic General Schools operate on two shifts.

Primary schools serve villages of 5 to 10 thousand population and teachers are, as much as possible, residents of the community. Primary schools average 1120 and 1325 pupils in the two districts with most operating on double shifts. Secondary school enrolments average 1000 and 900 and operate on single shifts. As secondary schools serve up to 10 villages, teachers can not always be accommodated in the locality of the school. Thus, accommodation of one room is provided for many of the teachers.

The number of classrooms can be roughly estimated by taking the number of classes in kindergarten and upper secondary levels and one half the number of sections in Basic General Schools. On this basis, it is estimated that Tien Hai District has around 800 classrooms and Xuan Tuay District 1150.

1986 Storm Number 5

The Provinces of Thai Binh and Ha Nam Ninh are located on the coast of the China Sea some 150 km. southeast of Hanoi. They lie on either side of one of the outlets of the Red River. At about 10 p.m. on 5 September 1986 storm number 5 struck these provinces causing extensive damage in both. The recorded wind speed has been quoted at 120 to 140 km per hour. As this measurement was most probably taken some distance inland, it is most probable that the speeds were considerably greater along the coast. Judging from the extensive damages to tile roofs and the over-turning of brick walls speeds well above 140 km must have occurred in many areas. The storm abated after about four hours. It was reported that the eye of the storm came inland in Xuan Thuy District of Ha Nam Ninh Province in the area of Tho Nghiep. Tie:) Hai District in Thai Binh province which is across the river from Xuan Thuy District was also heavily affected. Table 1I.b gives data on the damages suffered by the 11 schools visited during the field trip.

Storm Damages

The extent of the damages was very considerable. Thai Binh Province reported 800 classrooms destroyed and 4800 damaged while Ha Nam Ninh Province reported 413 as destroyed. The value of damages was estimated et 400 million and 1000 million dongs respectively. Tien Hai District reported that 134 of its total of 800 or so classrooms were fully destroyed

9

Table 1I.a Educational Data on Provinces and Districts visited

_____________-______----------------------------------------------------

Kindergarten Basic General Schools ________---__---------~~---~~~-~~~~~-~~---~~~-~~~~~~

No. of No. of No. No. of No. of No. Schools Classes Enrol. Schools Classes Enrol.

________-____--__--~~~~-~~~~--~~----~~~~~~----~---_--------------------~

Thai Binh Prov. 300 - -

Ha Nam Ninh Prov. .- 542 - - _____________-_-__-_--------------------------------------------------- Tien Hai Dist. 32 220 6453 32 983 35800

Xuan Tuag Dist. 41 470 12260 43 1112* 57000 z

________-_________--------------------------------~---------------------

Note: Figures given are rounded data supplied by provincial and district officials.

_--~-----------__----~---. Upper Secondary Schools

No. of No. of No. Schools Classes Enrol.

_-------_-------__--_____

27

54

3 57 3000

4 96* 3700 ~_-~~---~~---~-------~---

Total Thai Binh

Ha Nam Ninh

-----_-----------_______ Teacher Training

No. of No. of No. Schools Classes Enrol.

.~~---~~-----~--~~-----~~-

450,000

670,000 ~--__---__-----~--__---~~

* combined equals 1208

.

. . . .

Table 1I.b Data on schools visited

___-----------------. 1. Dong Quy

2. Dong Xuyen

3. Dong Tra

4. Dong Hoang

5. Dong Lam

6. Dong Co

7. Xuan Tuay S.S.

8. Huyanh Son

9. Giao Ha

10. Tho Nghiep

11. Xuan Vinh S.S.

____----------- _---- TOTALS

______-_-------- ----

--

-L

___------- Pop.

____-------

5,000

4,500

4,500

80,000

7,000

10,000

90,000

_----------.

___-__-----.

_ _

--.

L

___-_----- Enrol.

---------- 925

1,049

1,354

1,150

950

1,024

1,000

1,500

1,700

780

----------

__--------

Cl.

---------

26+10

23+9

2+16+10

19+9

18

27+10

30+11

15

--------.

--------.

*excluded from total since other data lacking

___------ CR

before ---------

14

14

18

16

21

14

20

19

-

26

15

---------- CR

destroyed __--------

5

8

18

6

5

7

10

7

3*

11

4

.---------- 81

.-_-_---_-_ 46%

.--------- CR

Damaged _---------

11

6

10

6

7

8

12

20

8

---------- 88

---------- 50%

--

. - J . _

3 shifts

2 shifts

2 shifts

2 shifts

2 shifts

2 shifts

1 shift (2 teachers rooms destroyed)

2 shifts

(teachers rooms destroyed)

2 shifts

1 shift (20 rooms for staff)

--------------

--------------

and 400 lost their roofs. Xuan Tuay District reported that 369 classrooms were destroyed and 510 damaged out of an estimated total of 1150 class- rooms. While the figures may not be exactly comparable due to differing standards for defining the damages, the point is well made that damages were substantial.

An observation of 11 schools (9 Basic General schools and 2 Upper Secondary) indicated that out of 177 classrooms which existed before the storm struck 46 per cent were destroyed to a point where both walls and roofs had to be reconstructed and 50% required extensive roof repairs. Thus only 4 per cent of the classrooms escaped serious damage.

Most buildings were constructed in a similar fashion - with 20 cm thick load bearing brick walls around the perimeter and between classrooms. Lime mortar was used in most walls. Nearly all roofs were made of clay tile. The roof trusses and tile support systems show considerable variations. Trusses were made variously of steel, timber, bamboo and composites of reinforced concrete and timber or railroad rails and timber. Purlins and battens were normally of bamboo, though some timber was also used in the better buildings. In most buildings tiles at the gable end of the walls were embedded into the brick work and sealed with mortar. In the badly damaged classrooms there were no ring beams and the trusses were not tied down either on the long walls or on the verandah columns. Lacing with light gauge wire or vegetable material was used at some schools to connect rafters to purlins.

Failures were typically at the ridges and eaves but very often the entire roof was stripped of tiles. As very few of the trusses were braced they frequently tipped over pulling the purlins out of the end walls. This seems to have led to the collapse of many end walls. Furthermore once the trusses had fallen, side walls also collapsed. In some classrooms it was noted that failure of the trusses was due to their having been severely weakened by white ants.

Very few reinforced concrete structures were found in the schools visited. One RCC structure - perhaps 20 years old - was found to be in very bad condition and on the verge of being dangerous. The reinforcing steel had rusted and broken open the verandah columns as well as the covering on the bottom side of the roof slabs. This problem can, in part, be attributed,to the salt in the local sand and in water used for construc- tion. It is also due to providing insufficient concrete cover over the steel reinforcement.

Buildings Which Survived

At one secondary school several older buildings were seen which had survived the storm nearly intact. One of these had longitudinal cross bracing between trusses which was .the only example seen. The other relied Or: a verandah on one side and both ends to create a 45 degree corner bracing while the heavy timber used for the roof truss was firmly anchored into the side walls. Another building at the same school had a smooth finished roof made of flat tiles set into mortar. This building was some 40 years old and seemed to still be sound, though the interior spaces were not suitable for classroom teaching.

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Recent Reconstructions

Two styles of reinforced concrete structures were seen which had been put up since the storm.

One of these is a flat concrete slab roof structure supported on two transversal beams. While this structure eliminates the use of roof tiles it introduces the possibility of trapping water on the roof. This in turn can easily lead to water penetrating into , and through, the roof slab. The future consequences can be the corrosion of reinforcing steel and damages to the interior surfaces.

The other was a two storey structure which used brick bearing walls with a continuous RCC lintel and ring beam. The floor was of precast hollow panels 3000 x 600 x 200. These are commonly used throughout Viet Nam and can be lifted into place with a hand operated winch. However the end support of these precast units on the concrete beams is a problem.

One damaged building had been substantially reinforced by adding a bamboo truss in between existing timber trusses thus resulting in a span for the purlins of less than two metres. The purlins were of heavy bamboo and carefully attached to the trusses with pegs and lashing. As a result the tile roof had a satisfactorily uniform appearance. While this structure may not be able to withstand a very strong hurricane, it demonstrates that if the local materials of brick, tile and bamboo are judiciously used in unison a reasonably sturdy structure can result.

Materials, Workmanship and Maintenance

Normally, a well constructed and well maintained brick school building should have a serviceable life of over 50 years. Yet many of the brick buildings in Viet Nam have collapsed within 10 years under the wind forces of the typhoons.

In the course of the field trips to three provinces and a visit to the educational equipment factory in Hanoi, it has become evident there are a number of reasons for the failures. Materials must be correctly designed, manufactured to a high quality, delivered on si,te when needed without being damaged, installed correctly and rigorously maintained. Problems were observed in all these steps.

It was noted that clay masonry is the basic building material in Thai Binh and Ha Nam Ninh Provinces while in Hai Phong Province there was also extensive use of blocks which used cement as a binder. While the quality of the bricks is relatively poor, they could no doubt be improved with some development work. Decorative hollow clay tiles, on the other hand are seen throughout the region and have the appearance of being very well made. Walls are often made using lime mortar which was of varying quality. In some cases where the lime and sand were pure a fairly high strength has been achieved. Walls where impurities in the mortar, were evident often failed.

Clay tiles are widely produced and are used on over 80% of the buildings. The tiles tend to absorb moisture and also crack easily. During typhoons a large number of tiles are cracked, broken and removed

13

from the roofs. A large part of the damages to buildings during typhoons are a consequence of failure of the tiles. Sheet materials are seldom used and apparently not produced in significant volume.

Timber is in relatively short supply with the consequence that villages often use other materials such as iron or bamboo in roof structures. Bamboo is almost exclusively used for the purlins, small rafters and battens in the roof. There is no treatment of the timber or bamboo with the result that they are often attacked by white ants.

Steel is in very short supply in Viet Nam and is therefore seldom used in construction. An investigation was made into the ability of the educational equipment factory to produce galvanized steel straps which could be used to give integrity to the roof structures and for firmly attaching roof trusses to walls. These elements are crucial to making buildings resistant to tJlphoon forces as they can take the tension forces which result from the uplift on roofs in high winds. It would seem that the educational equipment factory could produce up to 1 million units a year. It was also suggested that these straps could be produced in the provincial vocational/technical education centres possibly as a part of the programme of linking education to productive work. The ability of these factories to apply galvanization of an adequate standard is unknown. The Hanoi factory can do galvanization of 5 microns but may not have an adequate capacity to achieve the volume indicated above. The factory would need to receive the raw materials and to have three months notice to begin production.

In general the quality of construction of the damaged buildings was low. While there are problems at all stages, i.e. with the design of materials, the quality of materials produced and in construction techniques, there is a substantial scope for making local materials perform better through improving construction techniques. One major problem is the absence of tension members in the structures. Tension straps in the roofing system, ring beams at the tops of walis and vertical ties between ring beams and foundations are hardly ever used.

Once constructed buildings tend to be left unattended. Systematic repair of broken hinges and latches, patching of water leaks in roofs and walls, and painting of wooden components of buildings would contribute greatly fo the longevity of the buildings.

The Field Trip in Photsraphs

A number of pictures were taken during the field trip using both black and white negative film and colored Polaroid film. The Polaroid shots were used to produce an instant record of damages which were noted in the buildings visited. These were used during the workshop and training course to illustrate various points made by the UNESCO consultant. These have been made into a book by the MOE for future reference.

Following are prints'of a black and white phatographs taken during the field trip. Notations are given on each to indicate the strong or weak points and to indicate where improvements might be made.

14

TYPICAL DAMAGES

Buildings with minor damages lost tiles at the edges and corners of the roofs.

Buildings with more severe damages lost not only the tiles, but the roof structure as well.

The most severely damaged buildings suffered collapse of brick walls.

15

CONCRETE WORK IN TYPICAL NEW CONCRETE AND BRICK CLASSROOM BUILDINGS

The roof will pond water and leak. Note lack of ventilation and unattractive design.

More attrative design of concrete and brick. Roof will pond water and leak.

Note crack along concrete beam which weakens support. This is the start of "concrete cancer". Concrete work demands excellent workmanship and design and control of materials quality.

16

---- _.---_ - _..-. l_.--n.-._. . . --__-_ .-.___.. .l..._-_. -.- .._

Thin RCC slab. There is no cover to protect reinforcement rods. Thus rust attack has led to expansion of the rods and cracking of the concrete. See also below.

Precast columns or slabs removed from building because they were attacked by concrete cancer. Materials must be free of impurities such as salt which causes steel to rust.

EXAMPLES OF "CONCRETE CANCER"

Note insufficient 40 mm thickness of slab. Steel should have a concrete cover of at least 25 mm. Steel should not be covered with materials which absorb moisture, such as brick.

17

18

ROOF FRAMING

This roof lifted off due to absence of fixing. The truss fell over due to lack of cross bracing and attachment to walls. Walls remained intact as they were not called on to transfer any load. However, note crack at the window. All elements of the roof frame should be tied together to create an integral, rigid structure.

This truss failed due to white ant attack and lack of maintenance action. Timber needs to be treated and if white ants do attack a structural member, it should be immediately replaced.

-...- I . ..- _.------ .-.l.-.. -... ------.-.----

ROOF FRAMING AND TRUSSES

Note truss with concrete bottom chord and absence of fixing to timber struts. It will fail in the next storm. Tie all members of a truss together.

The close spacing of purlins is excellent. This truss is too slender to carry the heavy forces on it. It will fail in the next storm. Note lack of longitudinal bracing and tie down to walls.

A well made roof. However the truss needs to rest on a good ring beam and be tied down to walls.

19

ROOF TRUSSES AND FRAMINING

A well made timber truss with an intermediate truss of bamboo which needs additional struts. Bracing between trusses is required. Purlin spacing and fixing is good. Roof frame should be tied to foundations via a I ring beam.

The same roof as above. The intermediate truss of bamboo installed after the roof was lost has resulted in an even roof without sagging.

When roof loads are transferred to a masonry wall, the wall may fail and crack. There is need for a bond beam and tie down. Such suspended cracked brick work is not safe.

9

-3

20

RWF FRAMING

This roof shows the work of a good tradesman. However there is no tie down between the trusses and columns. Note bamboo truss which has been added between timber trusses. A horizontal beam should be placed between piers to support bamboo truss. Trusses should be tied to the beam, and the beam tied to brick column and brick wall. A tension tie should be fit on the face of the column fixed to beam above and carried down to the foundation.

This tradesman understands that roofs need tieing down. However the joints are not tight and pins too small for wind loads. Note the bamboo as an over-batten. This detail demonstrate good intentions and theory but needs a little guidance to be made effective.

ROOF FRAMING AND CLADDING

Note stiffness provided by timber braces and struts. Note longitudinal beam over columns. Note large size of rafters and close spacing of purlins. Very good workmanship. To further improve resistance against strong winds the beams need to be tied down to the foundations and the timber members need to be well connected to each other.

See same building below.

Well built school. Note shape of dutch gable end which provides bracing. Note attempt to fix over rafters of brick on top of roof.

See detail of corner above

22

23

ROOF CLADDING

Note small battens rafters and edge beam. Battens must be larger and fixed to rafter which should be securely fixed to purlin which in turn, must be fixed to truss.

High pressure at perimeter removed roof tiles. Tiles not tied down.

-.--... _ ---

ROOF CLADDING

Detail showing good workmanship in traditional roof.

.

Traditional houses in Tien Hai District. The local tradesmen have understood need to have a strong roof ridge.

24

III. EDUCATIONAL BUILDINGS IN THE TYPHOON AFFECTED AREAS OF VIET NAM

by Department of Educational Buildings, Ministry of Education

PART 1. TYPHOONS AND CYCLONES IN VIETNAM: THEIR DAMAGES To EDUCATIONAL BUILDINGS

1. GEOGRAPHIC AND CLIMATIC FEATURES IN VIETNAM

1.1 Geography

The country of Viet Nam, S-shaped, stretches between latitude 8' 30 North and latitude 23' 22 North, and between longitude 102" 10 East and longitude 109" 30 East. Situated in the East of Indochinese peninsula, the country faces the Eastern Sea, a closed and large sea with an average depth of over 1,000 metres. The total sea area is 3,447,OOO square kilometres.

Geographically, the country gradually gets higher and higher from east to west with heights and plateaux about 1,000 metres above sea level; the highest peak being 3,143 metres.

1.2 Climate

Viet Nam has a tropical climate with monsoons. It is hot and humid with 2 seasons yearly. From May to October is the hot and rainy season the South East and South West winds prevail. From November to April, is the cold and dry season with North East and North West wind which is dominant.

The yearly average temperature ranges from 21,6 C in Lang Son to 26,9 C in Ho Chi Minh City.

The climate is frequently dominated by the monsoons. The winter monsoon (North East) blows in spells from November to April. In coastal areas from Quang Ninh to Binh Tri Thien wind force reaches to 5 or 6 (nearly 14 metres a second). The summer monsoon blows from May to October with the direction of South West in the South to the direction of South in Central Viet Nam and the direction of South East in the North with the force of 3 and 4 (Figure 111.1).

Typhoons frequently attack coastal areas in Viet Nam usually from June ,to November. As the year draws to its end cyclonic storms batter the more Southern coastal areas. These typhoons often form themselves in the West Pacific within latitude 10 to 20 North, longitude 123 to 130 East, or right in the Eastern Sea between latitudes 7 to 20 North and longitudes 112 to 120 East.

The average quantity of rain every year is roughly 2,000 mm.

2. DAMAGES CAUSED TO EDUCATIONAL BUILDINGS BY TYPHOONS

2.1 Typhoons and storms in Viet Nam

25

WA b-h1 c -to +--

---.+-p winter

4 - -49 summer /-

Fig. III.1 Monsoons in Viet Nam.

26

monsoon

monsoon

According to statistics collected over the past many years the annual number of storms averages 3,9 and most frequently strike coastal areas of Viet Nam. It sometimes happens that there are years with either no storms at all or 7 to 8 storms. If low tropical. atmospheric pressures are included (LTAP) the annual number of storms averages 7,2 and sometimes there are 12 to 13 storms striking a year. (LTAP means propitious whirlwind with wind force of 6 or 7).

Some 44% of storms that strike Viet Nam have wind force of 10 to 12, that is wind speeds of 30 metres a second to 42 metres a second (see also Part 4).

Storms usually move at the speed of from 10 km/h to 20 km/h, therefore in places where the storm centres pass by there is strong wind changing its direction and blowing hard for 3 to 4 hours running. Besides, there are storms, moving very slowly, which strike the land with strong wind blowing for 10 to 12 hours running.

Storms carry heavy rain with them. Each storm brings to the places it strikes about 10% to 15% of the annual rain amount. In some cases, a storm can 'bring about 1,200 mm of rain i.e. 50% of the annual rain amount in that locality.

Heavy damages are caused to the localities struck by storms with forceful whirlwinds and protracted rains.

Statistics show that nearly 75% of storms that strike Viet Nam mostly affect coastal areas in the North from Quang Ninh to Binh Tri Thien, while only 25% of them hit coastal areas in the South, from Quang Nam - Da Nang southwards. Especially, in the Cuu Long River Delta there are practically no hurricanes.

Besides, there are cyclones. These cyclones with violent whirlwind limited in time and scope of activities have got high speed, no less strong than storms and affect an area, hundreds of metres wide and a few kilometres long. Within dozens of minutes, such cyclones can level to the ground hundreds of houses and even electric poles. The difference of cyclones from storms is that instead of forming themselves in Eastern sea in Northern hemisphere or in West Pacific cyclones often form themselves almost anywhere in coastal areas in the Delta, the midlands and mountainous regions west of Viet Nam. Cyclones and whirl- winds most frequently occur in North Viet Nam.

2.2 Scope of Damages cause,d by storms

Forming itself on the Sea, a storm muves from east to west, then strikes land. Its usual direction is Eastward, South Eastward to Westward, North Westward, then changing over to the direction of East - West and finally East, North East to West, South West.

Sometimes, a storm moves very swiftly in almost a straight line, from the Sea to land, then dissipates within 2 to 3 days. Yet, there are some storms that move very slowly in complex circles or trajecto- ries, with directions changing many times and that last for 2 to 3 weeks.

27

A few storms form themselves and dissipate right on the sea, but most of them hit land before their disappearance.

In Viet Nam, statistics and observations show that in the North storms often weaken and disappear in the Midlands, and in the Central part in mountain areas and Western plateaux (Figure 11X.2>.

In North Viet Nam, the average number of storms accounts for nearly 75% of the total number of storms that strike Viet Nam. Following are the 11 localities often suffer from damages by typhoons: Quang Ninh, Hai Phong, Hai Hung, Ha Bat, Thai Binh, Ha Nam Ninh, Hanoi, Ha Son Binh, Thanh Hoa, Nghe Tinh, Binh Tri Thien. In the South, affected areas are Quang Nam - Da Nang, Nghia Binh, Phu Khanh, Thuan Hai.

2.3 Damages caused to educational buildings

Following is the number of school buildings and classrooms as well as the number of students in typhoon affected areas {Tables III.a- d).

In provinces that are frequently struck by typhoons there are 11092 kindergarten schools, general education schools and secondary education schools with 131,113 classrooms and 7,566,071 students accounting for 54.8% of the total number of classrooms and 51.2% of the students throughout the country.

School buildings and classrooms in these areas can be divided according to quality of construction as follows:

- Strongly constructed buildings in reinforced concrete 15.5% - Buildings, with brick walls, tile roofs, etc. 58.0% - Thatched roofs, bamboo structure, classrooms 26.5%

This shows that the number of schools and classrooms vulnerable to typhoon damages amounts to 84.5%.

Destruction and damages caused by typhoons are extremely great. In many areas, schools and classrooms were destroyed or damaged for they had to suffer from one storm after another with no time for repair in between.

2.4 Causes of damages

A typhoon is a natural phenomenon with strong wind and heavy rain that can cause terrible destruction and damages in a large area hundreds of kilometres in width along its path. Up to now, with his knowledge, man is in a position to subdue to a certain extent typhoon damages. This depends on many factors both subjective and objective. In Viet Nam, the damage and destruction are due to the following.

2.4.1 Social and economic causes

The highly affected areas are esactly those suffering from heavy war damages and destruction over the past decades. Many towns and

28

Fig. III.2 Typhoon affected areas in Viet Nam.

29

villages were completely destroyed. Since the restoration of peace, people have returned to their naive land, therefore, a lot of houses and other kinds of construction need to be built at once to meet the immediate requirements. Within 10 years after National liberation hundreds of classrooms have been temporarily built with various kinds of materials for the children to go on with their learning.

These makeshift classrooms are not up to modern standards desired by Ministry of Education, and are liable to damages caused by time and nature. Due to limited resources, Ministry of Education has aimed to improve the learning conditions for our pupils. As a result, throughout the country there are about 75% of schools and classrooms are made of bricks and tiles.

Table 1II.a Schools in typhoon affected areas 1986 - 1987 school year

- i

Names of provinces 'Number of Schools I

!- - ._..- -_---_l__ ! Kindergarten

7‘ 1

_-.-__- .--- General

Education

I ,- ._WIW_

Secondary 1 Education 1

Total

i Highly typhoon affected j

Quang Ninh 89 Hai Phong 180 Hai Hung 427 Ha Bat 118 Thai Binh i 290 Ha Nam Ninh I 474 I Hanoi 378 Ha Son Binh I 168 Thanh Hoa 512 Nghe Tinh f / 635 Binh Tri Thien I 295 --------------------______I_________ t- 1 Total I

236 221 429 347 300 526 447 443 622 818 487

22 27 45 28 27 52 57 44 45 68

z

347 428 891 493

i 617 I 1,052 1 882

655 11,179 11,521

33 i 815 . ..---e -----.- b--e--- ---- I -----

8,880 ----------------------------------- e--e-

t

Less typhoon affected j i

1 i I I

Quang Nam - Da Nang 205 ; 389 624 Nghia Binh i 272 c 410

/ ;; i 715 Phu Khanh i 160 1 282 ! 28 I 470 Thuan Hai I 146 : 246 f 11 1 403 ~----_,-__,-,-_,---_,-~-------------i----------~----------~----- Total

I 2,212

30

Table 1II.b Classrooms in typhoon affected areas 1986 - 1987 school year

Names of provinces I Number of Classrooms I... ._-..-. _--_ -. _.+._ ~.i-.----...-- I _I _--_- ._. . ..- . __. . ‘,

1 Kindergarten 1 General i Secondary i Total j Education I Education j

i _Highly typhoon affected i I

i

i

Wang Ninh I Hai Phong Hai Hung Ha Bat Thai Binh Ha Nam Ninh Hanoi Ha Son Binh Thanh Hoa Nghe Tinh Binh Tri Thien -a------------------e-v Total --------_----.---------_-

Less typhoon affected

Quang Nam-DaNang Nghia Binh Phu Khanh Thuan Hai ------------------------ Total

757 1,545 3,075 2,204 2,160 4,459 2,976 1,890 3,311 5,147 2,072

2,695 : 239 ; 3,694

j 6,178 3,213 1 1 336 ; 669 1 5,094 9,922

/ 5,624 1 482 3,905

+ j

j 8,310 444 j 6,509

8,168 1 865 13,492 I 6,842 I 816 ilO,

! 6,121

j 527 i 8,538 797

1 8,388

1 : i 12,496

11,930 1,301 .18,368 I 5,542 : 424 ; 8,038

------,---,---L--~--~----k-~---.H-m.~-Le-~e-

105,092 ------------",-l'---‘----------I------------- I

1,934 1 5,550 i 386 7,870 1,905 i 6,700 j 493 i , 9,098 1,357 * 4,137 1 293

621 i ; 5,787

2,479 166 1 3,266 -----,-------,----------,--,,-,----,--

26,021

31

Table 1II.c Students in typhoon affected areas 1986 - 1987 school year

Names of provinces ,Number of Students 1

( -_..- ._._ - _..__ _.__ . . !

_ . - _ _. . _ -- ,. _ \ Kindergarten j General 1 Secondary 1 Total \ f Education 1 Education j I

Highly typhoon affected f ,

Quang Ninh Hai Phong Hai Hung Ha Bat Thai Binh Ha Nam Ninh Hanoi Ha Son Binh Thanh Hoa Nghe Tinh Binh Tri Thien

19,901 49,019 97,329 66,658 65,487

119,962 98,107 55,682

120,665 147,143

62,722

i 145,104 i 247,090 i 444,214 j 383,796 f 303,684 j 544,707 j 545,401 j 330,359 1 533,374 f 692,914 j 358,698

.-w---_----w

i 1 1

19,065 32,067

; 44,262 : 27,491 ; 27,066 1 48,597 : 62,868 ; 37,968 ; 50,140 / 66,616 i 25,411

1

1184,070 j328,176 1585,805 ! 477,945

i 396,237 ,713,266 !706,376 i424,009 1704,179 :906,673 1446,731

Total 4 5,873,467 ---------------------------"-----------------------------------------

I i ,

Less typhoon affect& j [ I t I i I t I

Quang Nsm - DaNang : 55,638 1 358,099 / 31,826 1445,563 Nghia Binh 85,775 i 507,950 32,721

' 1626,446

Phu Khanh b 52,003 ; 304,346 22,564 1378,913 Thuan Hai 29,212 i 202,899 9,571 1'241,682 _----------_--_-----___I________________----------------~------ Total 1,692,604

Table 1II.d Damages caused by typhoons from 1977 to 1985

I Classrooms Kind of area

1 Destroyed EducatGal Equipment ! ._ ,. .__ ,. _., .____. .._. -r-.--.--.-. . . .

r-

_ .I.C__--._--.- -.-- I ._. e.- .._.-_ __.- ..---_ . ! Destroyed1 Damaged Desks (sets) j Books

I i I I

Highly typhoon ' I

affected ' 22,635 27,838 '; 107,227 13,443,ooo

Less typhoon ; I i i 1 affected I 3,198 : 4,497 i 18,371 I 515,000

i /

Total I

i 25,833 132,335 i 125,598 i 3,958,OOO

32

Furthermore, over the past years, educational development has exceeded economic development. There has been a decrease in investment for educational buildings as well as in the supply of basic building materials. Many schools, built by local people do not follow any recommended design as the Ministry of Education does not monitor or give any guidance to design and development of individual schools. Consequently, this leads to random school development. Many schools have been built at high costs but with low qualities.

In brief, the number of schools that can resist typhoons without any damage only account for 15.5%, thus destruction and damages are unavoidable.

2.4.2 Technical causes

(a) Planning. Due to the pressing needs for construction, planning for the building of many schools was not done or poorly carried out and consequently they suffered from heavy damages when struck by storms. In this case, the choice of location is wrong.

There are a few examples.

Schools are built in open areas, exposing themselves to wind, so natural damages are likely to happen. (Figure 111.3)

Schools are located in high places or hills in the full force of wind.

Schools are positioned in places full of draughts. (Figure 111.4)

Many schools have got good places for construction, but general site planning is wrong so heavy damages are likely to occur. Here are some instances.

Rooms are arranged in line creating a wall against the wind. (Figure 111.5)

Rooms are arranged in the shape of H forming a bag full of wind. (Figure 111.6)

Trees are planted in wrong positions not leaving enough safe space so when there is a typhoon trees are broken and fall levelling houses to the ground.

(b) Design and structure. Among the causes that lead to the collapse of many constructions there are two main ones.

- Classrooms are too large in size. Most of the classrooms that have been constructed have the dimensions of 6 m x 9 m. The unsupported walls are too long to be strong enough to resist typhoons. (Figure 111.7) (see also Part 4)

33

Fig. III.3 Schools positioned in open places. Villages surrounded by bamboos.

Fig. III.4 Schools placed in a valley full draught.

34

.

Fig. III.5 Houses arranged in walls standing against the wind.

Fig. III.6 Schools arranged in t-4 shape forming a bag full of strong wind.

35

- Most of the classrooms are built without taking into considera- tion the force and pressure of the wind created by typhoons. They are only based on experience.

There are other shortcomings concerning components of the con- struction as follows.

- Typhoon affected areas are in csastal areas with very soft soil while the foundations have almost to ties, so rooms settle unevenly and foundations get broken. (Figure 111.8)

- Walls built either for force resistance or protection are very thin with no supporting pillars or ties so they are likely to get cracked when foundations sag. (Figure 111.8)

- Doors and windows with weak hinges all the more weaken the walls which are long and weak as they are. Doors and windows are usually the first point of collapse. (Figure 111.9)

- Trusses are made up of steel, wood or bamboo but are not bound together nor bound to the walls. Roof sheets are not tied tightly to rafters and roofs have no ceilings, thus they are easily get blown away. (Figures 111.10, 111.11, 111.12, 111.13, 111.14)

In general, every component has weak points, and all the components are not joined together into a solid block, so when the rooms are struck by typhoons they collapse in this order, doors and windows, then roofs and finally walls. (see also Part 4)

(c) Building techniques. Among other causes of failure there are some concerning building materials and techniques as follows:

- Bricks are baked in a primitive manner. They have low strength. Some bricks are made up of coal waste, not baked, and they have low bearing capacity.

- Mortar is of bad quality for sand is mixed with organic substances. In coastal areas, sand is mixed with saline matter.

- Building techniques are not satisfactory. Bonding lines coincide.

- The joints between components have low bonding capacity.

- Bonding lines are not filled up with mortar.

(d) Repair and2aintenance. ly done,

Repair and maintenance work is not regular- consequently the resistance of the construction declines.

Sometimes, serious damages occur, such as:

- Doors and windows are lost or damaged, wind blows off roofs. This leads to other damages.

36

Fig. III.7 Classrooms too large in size.

Fig. III.8 Classrooms with walls 110 nun thick, supporting pillars not strong enough to resist typhoons.

37

Fig. III.9 Doors and windows with hinges attached to walls, unable to resist strong wind.

Fig. 111.10 Rafters just placed on walls. Inverted trusses visible through windows.

38

Fig. III.11 Ends of rafters bolted to cushion unable to resist typhoons.

Rafter ends placed on pillars unable to resist typhoons.

Fig. III.12 Not tightly tied and attached together, roofs are likely to be blown up by typhoons.

39

Fig. III.13 Roofs without ceilings under them are likely to be blown up by strong wind.

Fig. III.14 Protruding roofs easily blown up by typhoons. D

40

- The mortar coat gets swollen and cracked, or the lime paint layer is not applied regularly, so the rain gets into walls. This lessens the bearing capacity of the walls.

3. LESSONS AND EXPERIENCES

From an analysis of the causes of damages mentioned above we can draw the following conclusions:

- The construction of educational buildings over the past years is only aimed at quantity rather than at quality.

- Unplanned development of schools does not correspond to economic management. .

The work of monitoring and guidance is neglected, norms and standards are not sufficiently defined. Research work and design work have not received close attention. Guidance and inspection work is neglected. No exchanges of experience have taken place.

PART 2. MEASURES AGAINST TYPHOON DAMAGES I_--

On the basis of an understanding of the causes of typhoon damages we can propose the following measures:

1. PLANNING FIEASURES

1.1 Choice of location for school construction

Along with economic and technical reasons, the choice of location for construction should take into account the advantage of the geographical situation that can reduce or prevent the effects of typhoons. In concrete terms, this should be:

- that schools should be built in places with advantageous geographical location that can provide protection from typhoons. It is necessary to take advantage of the existing houses, buildings, trees, bamboos, etc. that can act as shields for schools. (,Figure 111.15)

- that schools should be built on foot of hills, mounds, the height of these hills or mounds can bar the wind and its damages. (Figure 111.16) (see also Part 4)

1.2 Surface planning

What should be done are as follows:

- Choice of proper sizes for classrooms; avoidance of long blocks.

- Rational arrangement of buildings in geographical locations that can reduce or prevent typhoons.

41

--_- _..__- .---

--2__--

-

Fig. III.15 Classrooms situated behind tall buildings.

Fig. III.16 Classrooms situated behind mountains barring typhoons.

42

1.3 Planting trees for protection

Beside taking advantage of the existing village buildings, bamboos and lines or blocks of trees, we should locate new trees for shade or for surrounding the school properly in lines so as to provide protection. In doing this, it is necessary to:

- choose trees that can grow fast;

- choose trees with deep roots;

- choose trees with needle shaped leaves that can resist cyclones;

- decide the thickness of each line of trees and the intervals on the basis of windforce;

- make sure that there should be rational distance between trees and classrooms so that in case they fall down they will not strike the rooms.

2. TECHNICAL MEASURES

2.1 Concerning structure

Statistics show that in typhoon affected areas small sized classrooms can be built. Each classroom can provide 1 m2 a student. Following are some statistics for reference.

The average number of students per class:

- Kindergarten: 25 - 30

- Primary education: 30 - 35

- Junior Secondary: 35 - 40

- Secondary (Senior): 40 - 45

Classrooms should be of the following sizes:

- For 30 students: 5,4 m x 6,6 m

- For 40 students: 5,4 m x ?,2 m

These small sized classrooms can easily be repaired and maintained to resist typhoons a-t the time of limited resources. (Figures III.17 and 111.18) (see also Part 4 and Chapter IV)

Moreover, there should be 2 or 3 classrooms joined together only 20 to 22 metres in length. (Figure 111.19)

Overhanging components should be avoided in order not to be blown upwards by strong winds.

43

Fig. III.17 Small-sized classrooms (30 seats) restricting typhoon damages.

12400 1 2400 1 I ---Y-=-t-

Fig. III.18 Small-sized classrooms (40-42 seats) restricting typhoon damages.

44

_.

It is necessary to take into account wind force while a typhoon is raging. Each component of the construction must meet the following requirements:

Foundations:

- Foundations should be strong enough to resist all kinds of forces affecting them.

- There should be foundation ties to prevent cracks of walls when the earth settles.

- There should be .joints allowing for differential settlement when the site is in geologicaliy complex or foundations are long.

- Foundations should be in virgin layer of earth at the depth required by accepted norms.

Walls:

- Walls should be strong enough to resist all kinds of force.

- There should be ties inside them.

Doors and windows:

- To ensure the connection between doors and windows to resist typhoons, doors and windows should be of 2 kinds: Door frames fastened to walls with hook anchors; or sliding doors close to walls with moulds fastened to walls. (Figure 111.20)

Roofs:

- If there are enough building materials, roofs should be made up of concrete and steel.

- If roofs are sloping and covered with tiles, fibre-cement, or aluminium sheets, they should meet the following requirements.

: There should be ceilings, best made up of lath and plaster to keep cool and to resist rain and wind;

: Roofs should be of 30" (see also Part 4).

‘ Different parts of roofs should be closely fastened to . each other, purlins to trusses, trusses to walls, in both the horizontal and vertical planes. Beams and other parts should also fastened to trusses and to roof sheets.

: Trusses should be fastened to walls with steel hooks.

45

Fig. III.19 Classrooms should be in lines of 2 or 3 classrooms only.

Fig. 111.20 A kind of sliding windows resistant to typhoons.

46

Application of traditional experience

Vietnamese folk snd traditional architecture reflected in Buddhist temples that have been standing firm against typhoons for centuries shows that we should study and learn from past experience of the traditional architecture and apply it to the construction of typhoon resistant schools.

- Roofs should be thick and heavy to keep cool and to resist typhoons.

- Houses should be built on wood frame and pillars firmly fixed on a floor surface.

- With thatched roofs we should learn something from the bamboo net attached to roofs or bamboo poles attached downward from top of roofs (over-battens) and fixed to the ground around the house.

3. ADMINISTRATIVE MEASURES

3.1 Design and construction

It is necessary to:

- Revise the existing standards and regulations, and if necessary, develop certain standards and regulations for design and construction of schools in typhoon affected areas.

- Develop regulations for strict examination and inspection of designs.

3.2 Model designs and research work

It is necessary to:

- Carry out studies in order to establish diagrams of force resistance and make calculations to determine the shapes and dimension of all the components;

- Carry out studies on types and models of building materials to be used in school construction, paying attention to the use of materials available in each locality.

- Carry out studies and prepare prototype designs for classrooms of different sizes.

- Study measurements of general planning for schools of different sizes in typhoon affected areas.

-- Study details of doors, rafters and other forms of joinery.

- Study and select the kind of trees to be planted for protection, distance and density of lines of trees against typhoons.

47

Fig. III.21 Classrooms with ceilings under them as hard surface restricting typhoons from blowing up roofs.

Fig. III.22 Roofs of 30 degree slope Roofs of 45 degree slope preventing likely to be blown upwards them from being blown up by typhoons by typhoons. and leakage due to heavy rain and

strong wind.

48

.

Fig. III.23 Steel anchor fixed from rafter end to foundation.

Fig. III.24 Linkage from roofing materials with roof frames to restrict damages by typhoons.

49

3.3 Administrative work

It is necessary to:

- Develop regulations on administrative responsibilities concern- ing designs and construction of schools in typhoon affected areas.

- Develop sets of prototype designs for school development, for different kinds of~classrooms, with structural details.

- Organize design work and prototype construction of different kinds of typhoon resistant classrooms.

- Finalize and sum up experience in school construction for exchange and dissemination.

PART 3. CONCLUSIONS

Some 54.8% of schools with'51.2% of the total number of pupils throughout the country are.located in typhoon affected areas. In these areas, every year about 6,000 to 7,000 classrooms get damaged or destroyed and hundreds of thousands of desk sets and textbooks are spoiled due to typhoons.

The serious thing is that beside the considerable material losses, millions of pupils have no classrooms and have to learn in 3 or 4 shifts in makeshift classrooms, in offices or local people's houses. This situation lasts for months, badly affecting teaching, learning qualities and pupils' health.

So far, we have only come up with passive and temporary solutions to the problem when a typhoon comes.

After the typhoon is over, teachers md pupils try to build again their classrooms with the remaining bricks, tiles, etc. Other concerned governmental. services in dif%erent localities supply them with tar paper (to be used as sheets for roofs) and a limited budget to restore the damaged classrooms. Usually it takes a few months before everything comes back to normal.

The problem repeats itself annually depleting our material resources, poor as they are. It is now high time we should take up necessary measures against it to consolidate our educational buildings.

This workshop is the first step enabling Viet Nam to be aware of the problem, to evaluate the causes of damages and destruction in the past years as well as measures to be taken against the problem in the near future. This also is a change for educational builders and managers to master some theoretical aspects and technical experience concerning typhoon resistant schools development from other countries in Asia and the Pacific. On that basis we should renovate our ways of thinking and action.

It is necessary to implement the recommendations approved at this Seminar step by step.

The problem should be solved on an economic and technical basis. In recent years, SRV Ministry of Bducation has been given both technical and financial assistance from GNESCO-PROAP. This workshop is an example. It is our great hope that over the next years, UNE'SCO-PROAP will continue their support and assistance for our Project on typhoon resistant schools development as already agreed upon.

PART 4. COMMKNTS ON REPORT BY K.J. MACKS

PART ONE : Wind speeds -

Meteorological data on wind speeds and pressures may be inaccurate due to location of anemometers at some distance from coast and their inability to survive storms without breaking. Actual 5 second gusts on the coastal areas may have exceed 50 m/s (180 km/hr).

Para 2.4.2(b) - Classroom size

The comment is made that classrooms are too large and cannot resist typhoon forces. In fact the problem is that the walls are not stable enough to resist the forces. Therefore action to make the walls stronger would be a better policy than making rooms smaller.

Para 2.4.2(b) - Continuity of correction

The causes of failure are correctly identified:

-

Trusses not tied together Trusses not tied to walls Walls unable to transfer loads (no Walls not tied to foundations Lack of vertical tension component Lack of bracing in roof framing Lack of bracing in wall panels Lack of reinforcing in foundations

ring beam at top}

in walls

Door and window hinges weak and poorly fixed Inadequate design input to schools Too much use of poor materials Inadequate workmanship and supervision Poor or no maintenance of completed buildings

PART TWO

Figure 15, para 1.1

Where schools are located behind high buildings in order to get their protection they should not be sited too close to the protecting building otherwise they will be affected by higher wind forces caused by turbulence as the wind passes around the corners of the high building. It is suggested that a distance of from 80 - 100 m be a minimum space between the

51

high building and the school.

Para 1.3 Tree protection -

Tree protection and other landscape techniques are good but only if the trees are capable of withstanding the wind forces and are not easily broken. Research in this area is needed.

Para 2.1 Classroom size

Reducing the size of the classroom will not avoid problems of poor design and construction in wall and roof areas.

Para 2.1 Roof slopes

Wind forces on roofs change from suction on slopes of less than 25-27" to pressure on roof slopes pitched at 30-40".

Steep slopes on roofs cause special problems as the ridge is affected by high turbulence and this creates pressure. The result is that the high roof has to transfer a large wind load which tends to overturn the building.

52

IV. GENERAL PRINCIPLES OF EDUCATIONAL BUILDING DESIGN WHICH HAVE RELEVANCE TO TYPHOON AFFECTED AREAS

.

by John Beynon Principal Architect, UNESCO, Bangkok

Educators often complain that their requirements as school building users go unheeded by architects; architects complain that engineers insist on structural solutions which interfere with architectural concepts; and engineers ere often baffled as to why such a dialogue need to take place at all. This short paper is intended to review some of the principles of educational buildings (in particular teaching spaces) in such a way as t.0 show how solutions can be found which will meet the desires of all three professional groups. As the subject of the training course is educational buildings in cyclone affected areas, this paper looks particularly at the special needs of these schools. Cyclone areas, it is worth noting, are all located in the tropical zones of the globe.'

1. Optimal Learning Environments

Lighting. Light levels in classrooms must be relatively high - from 100 to 300 lux - and should be obtained through daylighting. This requires large wall openings of 15 to 45% of the floor area. It is also preferable to have bilateral lighting which makes seeing easier for learners.

These two requirements mean that schools must have large window openings. This can pose problems for the architects and engineers who need to brace these buildings well. (Figures IV.1, IV.Z>

Ventilation. It is the seated children who need to be made comfortable. K&-efore, ventilation openings should be placed in walls at a height corresponding to the seated children. It is also important to reduce radiant heating from the roof surfaces which are normally exposed to the SUIl. It is essential therefore, that teaching spaces have ceilings located well below the roof and that the space between roof and ceiling be well ventilated to take away the hot air which builds up between them.

Providing permanent ventilation openings on either side of a classroom has the advantage of lowering internal pressures during strong winds. The installation of of a ceiling can benefit the design because if it is made of solid material it can provide diaphragm action. (Figures IV.3, IV.4)

Buildings need to be oriented so as to catch the prevailing winds. This can create problems for designers as it may also be the orientation which is most liable to cause damage by cyclones. (Figure IV.5)

Sun Control. The windows of teaching spaces should be oriented to the North and the South to permit the best control of the direct rays of the SUll. Again, this may result in bad orientation as regards cyclone and their associated wave surges. (Figure IV.l, IV.5)

53

Acoustic. It is difficult for most teachers' voices to be easily heard for more than seven meters. This means that classroom should not be more than about eight meters long. (Figure IV.6)

2. Optimal Teaching Environments

Classroom size. The basic determinants of classroom size are the number of students to be taught in a class and the amount of space which is to be given to each student as well as to the lecturing space and group work activities at the front and rear of the room. The research which has been done indicates that if students are provided with double desks having adequate space to write while referring to an open textbook desk tops should be 1100 mm x 450 mm for primary school students and 1100 mm x 450 mm for secondary school students. Aisle space should be at least 45 cm while 2 meters should be provided between the chalkboard and the first desk and 600 mm is needed to provide access to a tack board at the rear of the room. Figures IV.7 and IV.8 give the basic data which can be applied to classroom design at primary and secondary level.

For reasons of acoustics and sight lines, it is recommended to have seven rows of pupils or less. The table below shows the minimum area per place in which students can comfortably work.

CR capacity CR Area (ma) with 7 rows size (mm) per place

Primary 6 per rank 42 4200 x 9040 0.90 8 per rank 56 5750 x 9040 0.92

Secondary 6 per rank 42 5100 x 9040 1.10 8 per rank 56 6950 x 9040 1.12

Flexible space. Class sizes are usually not the same which means that if equal size classes are provided some rooms will be over-utilized and others under-utilized. In these cases, there is a need for a variety of sizes of spaces in any educational institution. In many countries a long open hall school building which can be divided into spaces of variable sizes will be most efficient. (Figure IV.9)

This means that it is preferable to separate classrooms with partitions that can be moved. They should not, therefore, be structu- ral. On the other hand, cross walls provided excellent diaphragm action and on very long buildings may have to be provided every second or third classroom.

Chalkboards and other visual aids. Chalkboards need to be located so that there is a minimum of glare. When chalkboards are placed between windows the light contrast is so great that it is difficult to read the writing on the board.

To increase visibility, a curved "panoramic" board can be used and the solid sections of the walls should have at least one meter of solid wall projecting in front of the chalkboard location. Chalkboards may be mounted on light partitions which separate classes. (Fig. IV.10)

54

Display surfaces. Good schools have places to display the work of students and also to present supplementary learning materials such as posters. Since many of these materials are prepared with dark printing on light surfaces these can effectively be located between windows on the side walls, or on either side of the chalkboard. They may also be mounted on the walls at the rear of the classroom. (Figure IV.10)

Storage. All classrooms need a place to store teaching and learning materials. These can be provided as built-in units located next to the end walls and integrally surrounding intermediate columns. These can provide substantial stiffening if they are incorporated into the struc- tural design. (Figure IV.ll)

3. Protection from the Weather

Roofs. The width of classrooms is such that they are most easily spanned by trusses. If flat roofs are required and reinforced concrete beams are used these beams may have a very deep section; if they are kept shallow the costs rise substantially.

The use of trusses which give sloping roofs can result in a roof shape which performs well in strong winds. The use of reinforced concrete beams has the advantage that they can be cast integrally with a reinforced concrete ring beam. Flat roofs have the advantage in some countries that they make it easier to expand the building vertically. {Figure IV.4) However they collect water and are usually susceptible to leaking and to corrosion of reinforcement bars.

In many countries, it is desired that a verandah be provided along one side of the classroom. In all countries affected by cyclone it is desirable to have a substantial roof overhang to keep rain off the exterior walls.

Verandahs and large roof overhangs are among the parts of a building which are most vulnerable in strong winds. (Figure IV.l)

Walls. Exterior walls are required for reasons of security, to provide tackboard space and to keep out horizontally driven rain. They need corner bracing if they are to be kept rigid. In many countries, it is not yet feasible to use glass in the windows and they must, therefore, rely on wooden or steel shutters.

Walls, as well as roofs, must be designed to resist wind loads. Creative solutions may be required so that walls will meet the needs for strength as well as to provide satisfactory wall openings. (Figures IV.11, IV.12)

Floors. In many localities where there is flooding, one common architectural solution is to raise the building above the ground on stilts. Raising the building introduces additional costs and requires the engineers to find solutions which are structurally sound yet economical. Architects can take advantage of these raised buildings to provide covered play space or temporary classroom space. (Figure IV.13)

55

IV.1 DAYLIGHT 3 ILLWJNATION IV.2 MAXIMUM OPEIWBS

t_- RING EJEAM

<RING BEAM

II Jl

Iq 3 NATURAL VPUTILATIOF~ iv. 4 STRUCTURE

IV. 5 ORlENTATboN IV.6 ACOUSTICS

Fl Fl -.- -- -.- --

H H

-c J l,p -c J l,p ‘- - ‘- - 45 110 45 110

--,-h :_ _ --,-h :_ _

2.00 Irn

?2 se

I -I -

Iv. 7 PRIMARY LEVEL IV.8 SE-Y LEVEL

56

IV. 9 FLEXIBLE SPACE IV. IO CllALHBOARDs /T~CKBOARDG

IV. 12, BRACING

RAY WE

IV. 13 BUILDWU ON STILTS

57

V. CONSIDERATIONS FOR THE DESIGN OF TYPHOON RESISTANT BUILDINGS IN VIET NAM

1. BRIEF COI'MENTARY ON WIND FORCE EFFECTS

Windspeed. The wind moves over the ground at a certain speed normally referred to in metres per second (m/set), kilometers per hour (km&r) or miles per hour (miles/hr). In a cyclone or typhoon as in all wind environments the wind fluctuates and changes speed rapidly so that in a period of one hour, the forward wind speed is less than the maximum wind speeds which are achieved over periods of a few seconds only. The fastest design wind speed, which is the windspeed used in cyclone wind design, is that which occurs in a three second wind gust. This is referred to as the design wind velocity speed (V). Design windspeeds are normally those which occur at a height of 1Om above the ground on an open, inland terrain (category 2) and are based on a 50 year return of the wind event.

Height. The wind speed and wind gust varies with height, being slower near ground level where the wind is slowed down by the roughness of the ground, and faster at high altitudes where there is less interference to the wind's forward speed. This effect can be measured at altitude intervals of 10 meters and thus taller buildings are subjected to higher wind speeds than are low buildings. A design factor for different building heights has been established.

Wind Zone. Due to various geographical features cyclonic storms occur with predictable frequency in different locations. Cyclones are at their strongest over water and once they have travelled up to 50 km inland lose a substantial part of their force. By reviewing meteorological data of a country subjected to cyclones it is possible to define the zones which will get the strongest winds, strong winds and less strong winds. These wind zones are labelled A for wind gusts of up to 60 m/s, B for wind gusts up to 50 m/s and C for winds up to 40 m/s. Wind zones for Viet Nam are shown in Figure V.l.

Terrain Cate$ory. The smoother the ground surface the less friction there is for the wind and therefore faster wind speeds result at building height levels. Ground roughness characteristics known as terrain categories have been defined. In general these can be ranked as follows from fastest wind speeds to slowest: flat sea coast areas, exposed hills, level open ground, built-up suburban regions, forested areas and densely built-up city areas. A design factor for terrain categories have been developed and is given in Fig. V.2.

Wind Pressure. The wind speed can be converted into the pressures exerted on a plane surface normal to the wind. Table V.A covers all commonly used units of measure for both wind speed and free stream dynamic pressure. This table may be used for conversion of wind speed into pressures.

Structural Wind Loads. Winds create both positive and negative pressures on buildings. The windward planes which are tending to be pushed toward the inside of the building are considered to be positive external pressures. Those pressures which are caused by the airfoil effects of

59

Table V.A CONVERSION OF WIND SPEED TO FREE STREAM DYNAMIC PRESSURE TABLE

SPEED FREE STREMl DYNAMIC PRESSURE

m/set Knots miles jhr km/hr ‘lbf/f t2 kgf /m2 N/m2 kPa Pa

0.278 0.540 0.621 1.000 0.001 0.005 0.047 0.00005 0.447 0.868 1.000 1.609 0.003 0.012 0.122 0.0001 0.514 1.000 1.150 1.850 0.003 0.016 0.162 0.0002 1.000 1.942 2.237 3.600 0.013 0.063 0.613 0.0006 1.277 2.480 2.856 4.597 0.021 0.102 1.000 0.001 4.000 7.770 8.947 14.40 0.205 1 .oou 9.808 0.010 8.835 17.162 19.762 31.81 I .ooo 4.883 47.85 0.048

10.000 19.425 22.368 36.00 1.282 6.255 61.30 0.061

20.0 38.85 44.74 72.02 30.0 58.28 67.10 108.0

35.0 67.98 78.29 128.0 40.0 .77.70 89.47 144.0 40.3 78.28 90.14 145.1 45.0 87.41 100.66 162.0 50.0 97.12 111.84 180.0 55.0 106.84 123.02 198.0 60.0 116.55 134.21 216.0 65.0 126.26 145.39 234.0 70.0 135.98 156.57 252.0

75.0 145.69 167.76 270.0 80.0 155.40 178.94 288.0 85.0 165.11 190.13 306.0 90.0 174.83 201.31 324.0 95.0 184.54 212.50 342.0

lUO.0 194.25 223.68 360.0

5.124 25.02 2b5.2 0.245 11.53 56.29 551.7 0.552

15.69 76.63 750.9 0.751 20.50 100.0 980.8 0.981 20.81 102.1 1000. 1.000 25.94 126.7 1241. 1.241 32.03 156.4 1532. 1.532 38.75 189.2 185/f. 1.854 46.12 225.2 2207. 2.207 54.13 264.3 2589. 2.589 62.73 306.5 3004. 3. 004

72.06 351.8 34lf8. 3.448 81.99 400.3 3923. 3.923 92.55 451.9 4429. 4.429

103.80 506.7 4965. 4.965 115.60 564.5 5532. 5.532 128.10 625.5 6130. 6.13U

Formulae: P = 0.613V2 N/m2 (Pa) for V in m/set

P = 0.0625V2 kgf/m’ for V in m/set

P = 0.00256V’ lbf/ft’ for V in miles/hr

wind blowing around the walls or over the roofs create an external vacuum or a net negative (suction) external pressure which causes the various building planes to be pushed outward. It is the resultant sum of the positive and negative pressures which determines the total force on any plane of a buildings exterior.

As well as these external effects, a building can be pressurized with internal pressure (or vacuum) if openings occur in the building envelope.

As the external suction forces can become very strong* in high winds buildings tend to "explode". These outward forces are particularly strong on roofs where positive and negative forces combine and under some circumstances create a force stronger than the wind force itself. The Tables on Figures V.3a and V.3b indicate just how important this factor can be.

Roofs with less than 20" pitch are subjected to stronger external suctions than are roofs of greater pitch. Buildings which have an opening one side only are subjected to stronger positive pressures than buildings which are securely closed or which are open on both sides. Figure V.3a gives the pressure coefficients for buildings with openings on one side only while V.3b gives the pressures for buildings open on both sides.

As the wind passes over or around objects such as trees, ridges, fences, buildings, cliffs and valley, the wind becomes turbulent and causes local increases in air speed and wind pressure. The effect of these air pressures on the edges and perimeters of these obstructions can become much more severe than the normal wind pressure. These effects are catered for by allowing a local pressure factor "K" for critical areas of buildings. Figure V.4 shows the affected local areas of a building and gives the "K" factors. These loads are applied only in calculation of the forces on the cladding.

@her Effects on Wind Speed. The wind speed is also affected by atmospheric pressure, the ambient temperature and air density. However, for this paper, these effects are not taken into account and the factor used is 1.0.

Return Periods. Selective increases can be made to the design wind forces to cater for the expected life of a building or to give a building a greater factor of safety.

If a building is to remain intact for a once in 100 year event, it should be expected to resist the worst wind speed that could occur in a 100 year period. This wind speed would be higher than the worst wind speed expected in a period of 50 years. Therefore, the 50 year wind and 100 year wind can be referred to as specific events. Since this wind could arrive at any time, it would damage all buildings designed for a lesser event.

A 500 year or 1,000 year event would be described as catastrophic and, since meaningful records are not known for these periods, assumptions of their forces can only be assessed.

61

Post Disaster Functions. Important buildings, such as hospitals, police stations, post and telecommunication buildings, electricity generation and control buildings and refuge shelters (such as schools) should be expected to survive severe events such as cyclones so that they are able to serve their "post disaster function" during the recovery period.

Whilst most buildings should be designed for a 50 year event, most post disaster buildings should be designed for a 100 year event. The increase in design loads for the 100 year event is approximately 20%.

Cyclonic Overload Position. .--,- In considering the ability of building materials. and their fixings that resist the cylone wind loads, it is important to remember that the materials have to resist the maximum design forces only for very short periods of approximately 3-5 seconds. These short term loads may occur many times over the duration of a storm.

Some materials are able to accept short term overload situations with enough flexibility to recover to their normal strength. As timber will flex and recover, an overload allowance of 100% is allowed in the design of timber members for 3-5 second wind gusts. Steel members are permitted on overload factor of 33%. Brickwork, on the other hand, will not recover after cracking.

2. PROCEDGRE TO DETERMINE WIiVjD LOADS --

The following procedure may be followed to design a building which will be safe from damages in high winds.

Step 1: Collect the facts (a) Identify national wind zone (b) Identify wind speed (c) Identify terrain category (dl Identify height of building (e) Determine design pressure

Step 2: Determine the wind forces (a) Identify building dimensions, length, height, width (b) Determine co-efficients for wall and roof loads (cj Calculate structural loads - on walls

- on roof - on windows

Step 3: Determine wind loads (a) Work out actual loads (b) Determine structural lines of forces (c) Decide on lines of resistance - in wall plane

- in roof plane - in floor plane - in roof framing

62

Step 4: Design construction details and connections (a) Decide on details (b) Design resistance members ic) Design fixing details (d) Decide on materials to be used (e) Specify workmenship required (f) Check load areas and overturning moments

Some of the important points to be kept in mind as one works their 'May through this procedure are spelled out below.

1. The design wind applies to the wind speed at a height of 10m on a terrain category 2 site (e.g. at 10m on an airfield) and is based on a 50 year return wind.

2. If the site is more exposed (beside the,sea) the design wind is higher. If the site is more protected (in city areas) the design wind is less.

3. If the building is higher than 10m the design wind is higher. If the building is lower than 1Om the design wind is lower.

4. The design wind is to be converted to free stream dynamic pressure (e.g. kgf/mZ, or pounds per sq.ft. or kilopascals). This pressure becomes the design pressure.

5. This design pressure is increased or decreased by co-efficients which provide the actual pressure applied to various parts of the building's walls and roof areas and depends on the wind direction, the disposition of openings in the building and the roof slope.

6. This pressure or suction force resulting from the design wind and the building shape is to be added to the internal pressure generated inside the building which tends to push the walls and roof outwards. The resulting total pressure is the force to be resisted by the structure of the building and is referred to as the "Structural Load".

7. In addition, the cladding materials (roof sheeting and wall materials) are subjected to local pressures tending to pull off the cladding. These forces effect the cladding only and do not affect the structure.

8. The cladding of the central wall and roof areas carry the same loads as the actual pressure. However, perimeters of walls and roof areas carry a greater suction (50% greater). While the corners of the roof and sharp ridges and projections carry an even greater suction (100% greater). These forces or pressures affect the fixing of the claddings to their immediate supporting members and are referred to as "Cladding Load".‘

Table V-B gives a listing of the force of airfoil affect at different wind speeds.

63

Table V.B AIRFOIL AFFECT : WREN ROOFS FLY

Velocity

- I 1 Typical movement

0.00 m/set Dead calm - Birds fly 0.23 m/see Leaf moves 0.50 m/set Leaf flys 0.75 m/set Paper flys

O- 5 m/set 5- 10 m!sec

10 - 15 m/set 15 - 20 m/set 20 - 25 m/set 25 - 30 m/set 30 - 35 m/set 35 - 40 m/set 40 - 45 m/set 45 - 50 m/set 50 - 55 m/set 55 - 60 m/set 60 - 65 nt/sec 65 - 70 m/set 70 - 75 m/set 75 - 80 m/set 80 - 85 m/set 85 - 90 m/set 90 - 95 m/set 95 -100 m/set

Loose aluminium sheets fly I Loose galvanised iron sheets fly 1 Loose fibre cement sheets fly

I Loose concrete and clay files fly 1 Roof sheets fixed to battens fly DC3 aircraft take off speed [ Roof tiles nailed to battens fly Garden walls blow over

j

100 mm thick concrete slabs fly

150 mm thick concrete slabs fly

250 thick concrete slabs fly

1

3. COMPARISON OF INTERRATIONAL WIND CODES

To compare the wind codes of various countries, the wind forces created by a 50 m/set wind at 1Om above ground in Site Category 2 on a 50 year return period have been calculated in these codes as follows:

Viet Nam 112.9 kgf/m2 Sri Lanka 141.6 kgf/m2 Australia 153.4 kgf/m2 USA 1.56.0 kg-f/m2 Rritain 156.25 kgf/m2

It appears that from a comparison with other National codes, the Viet Ram wind code formula generates design loads between 20 to 27% less than those from the other comparative codes.

The large variation that results from using the Viet Nam code is called to the readers' attention. On the basis of this comparison it is suggested that the Viet Nam wind code be reviewed with an eye to updating.

64

For reference, the formulas of the various codes used are given below along with the calculations which led to the above results.

COMPARISON OF INTERNATIONAL WIND CODES

Calculations at 50 m/set Velocity (111.84 miles/hr)

Viet Nam --

40 = Lyg kgf/m' where: a = 0.75 +z

= 0.85 x 50' 16

V = wind speed in m/set

= 112.9 kgf/m'

Jnited States of America

Q30 = 0.00256 V2301b/ft2 where:

= 32 lbf/ft' Q30 = wind pressure at 30 ft

v30 = wind speed at 30 ft = 156 kgf/m'

lustralia

QZ = 0.6 V2z x 10-3 kpa where: % = wind speed at 10.0 m

= 1.5 kpa QZ = wind pressure kpa

= 153.4 kgf/m'

;ri Lanka

4 = KV;* lbf/ft' where: V2

= design wind speed = 0.00232 x 111.84' lb/ft' K = constant, zone l-0.00232

= 29 lb/ft' q = dynamic-pressure

= 141.6 kgf/m*

3ritish Standards

4 = KVs' where: VS

- wind speed = 0.0625 x 50' kgf/m2 K = 0.00256 lb/ft'

= 156.25 kgf/m' K = 0.0625 kgf/m'

65

4. WIND PRESSURE TABLES FOR VIET NAM

Taking into account the Rhove factors it is p0ssibl.e to generate tables which are suited for a specific country. This has been done fot Viet Nam. Table V.C gives thr design pressures for different wind zones in the country and with adjustments for each of the four terrain categories. Table V.@ to V.I give Design Loads on roofs for each terrclin category in the three zones. Separate tables are provided for roofs under 20" pitch and those over 20".

Table V.C PROPOSED WIND PRESSURES (Qz) VIET NAM DYNAMIC WIND PRESSURE - FOR SITE AND HEIGHT

Return period 50 years - 3 sec. gust in cyclone wind. P = 0.0625V2 kgf/m' for V in m/set. Assessed adjustments made to wind speed to suit site roughness and height.

Terrain Height Velocity Category Multipliel

(Site roughness) (meters)

1. Seaside

2. Rural open

3. Urban

4. city

Wind Speed Free Stream (m/set> Dynamic Pressure

Zone A Zone B Zone C Zone A Zone B Zone C

10 1.09 65.4 54.5 43.6 267 186 119 5 1.02 61.2 51.0 40.8 234 162 104

10 1.00 60.0 50.0 40.0 225 156 100 5 0.93 55.8 46.2 37.2 195 135 87

10 0.85 51.0 42.5 34.0 162 113 72 5 0.79 47.4 39.5 31.6 140 98 62

10 0.70 42.0 35.0 28.0 110 76 49 5 0.65 39.0 32.5 26.0 95 66 42

Qz - kgf/m' QZ - kgf/m' I

Notes: Most sites in Viet Nam fall in Terrain Categories 2 and 3. For post disaster buildings which should survive to serve the community immediately after a disaster (e.g. hospitals, police station, telecommunication buildings and perhaps schools if used as refuge centres), add 20% to all forces.

5. FORMULAE AND COEFFICIENTS FOR CALCULATING WIND FORCES

For f?ElSY reference by the render, the formulae and the coefficients used in this chapter are summarized and presented together.

1.

2.

3.

4.

5.

To convert wind speed to dynamic pressure

Qz = c v; Q, = Dynamic wind pressure

C = Coefficient vz = Dynamic wind velocity

Qz = 0.613V2 N/m' (pascals) for V in mlsec QZ = 0.0625V2 kgf/m' for V in mlsec QZ = 0.00256V' lbf/ft' for V in miles/hr

Design wind pressure on a surface

pz = Cp Qz PZ = Design wind pressure C p = Coefficient of pressure

The coefficient varies according to location of the surface and direction of wind.

Coefficient for height

The datum of 1.00 refers to a height of 10m on terrain category 2. Coefficients for other heights are:

O- 5 m high - 0.93 5- 10 m high - 1.00 - datum

10 - 15 m high - 1.03

Coefficients for terrain categories

Refer also to diagrams for degree of site exposure to wind. The datum is 1.00 at a height of 10m on terrain category 2.

Terrain Category 1 - 1.09 e.g. - at seaside Terrain Category 2 - 1.00 - datum - open country Terrain Category 3 - 0.85 - urban Terrain Category 4 - 0.30 - city centre

Local pressure factors to walls and roofs (K)

Refer to diagrams for typical areas affected.

General surface areas A - 1.0 Perimeter areas B - 1.5 Corners and gable ends C - 2.0

The local pressure factor is multiplied by the external suction on a roof or wall and affects the cladding and its supporting framework and fittings only. It must not be used to determine total forces on a building.

67

Table V.D DESIGN LOADS - ZONE A - PITCH (20'

1.8

P, = DESIGN PRESSURE

PI = INTERNAL PRESSURE

P, = EXTERNAL SUCTION DIAGRAM OF PRESSURE COEFFICIENTS

"

0 AREA A - P, + PI

AREA l3 - 1.5Ps+ I',.

AREA C - 2.0Ps+ PI

Qz = STATIC WIND PRESSURE

(to be multiplied by Qs)

STRUCTURAL LOAD P, = Q, (PI + P,)

CLADDING LOADS P, = Qz (K x Ps t PI)

TERRAIN CATEGORY

a -

2

3

4

HEIGHT

10 m.

5 m.

10 m. 225

5 m. 195

10 m. 162

5 m. 140

10 m.

5 m.

PRESSURE

QZ

267

234

110

95

DESIGN LOADS - Kgf /m2

-3

383 484 585

332 419 507

275 348 421

238 301 364

187 237 286

162 204 247 ----

;TRUCTURAL LOAD CLADDING LOADS*

I

ROOF LOADS - DOMINANT OPENING IN WINDWARD WALL

s

_-

WEND PEED m/set

65.4

61.2

60.0

55.8

51.0

47.4 ______

42.0

39.0

Local pressure factors must not be used in the determination of the total forces on a structure or a surface such as a wall or roof.

Table V.E DESIGN LOADS - ZONE A - PITCH )20”

TERRAIN :ATEGORY

cl AREA A-Ps+Pl I:::: AREA B - 1.5l’,+ 1’[

II AREA C - 2.0Ps+ Pi

Qz = STATIC WIND PRESSURE

P, = DESIGN PRESSURE

PI = INTERNAL PRESSURE

P, = EXTERNAL SUCTION

DIAGRAM OF PRESSURE COEFFICIENTS (to be multiplied by Qz)

STRUCTURAL LOAD P, = Q, (PI + Ps>

CLADDING LOADS P, = Q, (K x P, + PI)

HEIGHT

10 m.

5 m.

10 m.

5 m.

10 m.

5 m.

10 m.

5 m.

r PRESSURE

Qz AREA A AREA B AREA C 1.5 x Q, 1.85 x Q 2.2 x Q,

267 400 494 587

234 351 433 515

225 338 416 495

195 293 360 429

162 243 300 356

140 210 259 308

110 165

95 143

204

176

242

209 --___

*

DESIGN LOADS - Kgf/m2

rRUCTURAL LOAD CLADDING LOADS

ROOF LOADS - DOMINANT OPENING IN WINDWARD WALL

Local pressure factors must not be used in the determination oE the total forces on a structure or a surface such as a wall or roof.

Table V.F DESIGN LOADS - ZONE B - PITCH <20°

L-J AREA A - I?, + PI m AREA B - 1.9’s+ PI

m AREA C - 2.OPs+ PI

Qz = STATIC WIND PRESSURE

pz = DESIGN PRESSURE

PI = INTERNAL PRESSURE

Ps = EXTERNAL SUCTION DIAGRAM OF PRESSURE COEFFICIENTS (to be multiplied by Qs)

STRUCTURAL LOAD P, = Q, (PI + Ps)

CLADDING LOADS P, = Qa (K x Ps + PI)

I

TERRAIN :ATEGORY I

HEIGHT

2 10 m. 156 265 335 406 50.0

5 m. 135 230 290 351 46.5

3 10 m. 113 192 243 294 42.5

5 m. 98 167 211 255 39.5

4/ 10 m.

5 m. I

l- PRESSURE

Qz AREA A 1.7 x Q,

AREA B 2.15 x Q;

AREA C 2.6 x Q, s

WIND PEED m/set

186 316 400 484 54.5

162 275 348 421 51.0

76 129

66 112

DESIGN LOADS - Kgf/m*

TRUCTURAL LOAD

163

142 --

198 35.0

172 32.5

* CLADDIM: LOADS

ROOF LOADS - DOMINANT OPENING IN WLNDWCARD WALL

* Local pressure factors must not be used in the determination of the total forces on a structure or a surface such as a wall or roof.

Table V.G DESIGN LOADS - ZONE B - PITCH >20”

c

TERRAIN :ATEGORY

I AREA A - F, + Pi I::::::.I AREA B -. 1.5P,+ Pi

m AREA C - 2.OFs+ PI

Qz = STATIC WIND PRESSURE

P, = DESIGN PRESSURE

PI = INTERNAL m7Essum P, = EXTERNAL SUCTION

DIAGRAM OF PRESSURE COEFFICIENTS (to be multiplied by Qz)

STRUCTURAL LOAD P, = Q, (PI + Ps)

CLADDING LOADS P, = Qz (K x P, + PI)

-

--

HEIGHT

--

10 m.

5 m.

PRESSURE

Qz

186

162

10 m.

5 m.

156

135

10 m.

5 m.

113

98

10 m. 76

5 m. 66

DESIGN LOADS - Kgf/m*

AREA A AREA B AREA C 1.5 x Q x 7. 1.85 Q, 2.2 x Q,

279 344 409

243 300 356

234 289 343 50.0

203 250 297 46.5 I

I 170 209 249

145 181 216 ~-

114 141 167

99 122 145

s WIND

FEED m/.sec

54.5

51.0

42.5

39.5

35.0

32.5

ROOF LOADS - DOMINANT OPENING IN WINDWARD WALL

Local pressure factors must not be used in the determination oE the tota. forces on a structure or a surface such as a wal.l or roof.

71

Table V.H DESIGN LOADS - ZONE C - PITCH (20"

0.9 1.3 1.8 T &

T

TERRAIN :ATEGORY

1

2

3

*

I AREA A - Ps + F, . . . . I .: . . . . . . AREA B - 1.5Ps+ PI

I AREA C - 2.0Ps+ PI

Qz = STATIC WIND PRESSURE

pz = DESIGN PRESSURE

PI = INTERNAL PRESSURE

Ps = EXTERNAL SUCTION DIAGRAM OF PRESSURE COEFFICIENTS (to be multiplied by Qz>

STRUCTURAL LOAD P, = Q, (PI + Ps>

CLADDING LOADS P, = Q, (K x Ps + PI)

DESIGN LOADS - Kgf/m*

10 m. I 119 I 202 5m* w- 10 m. 100 170

5 m. 87 148

10 m. 72 122

5 m. 62 105

10 m. 49 a3

5 m. 42 71

STRUCTURAL LOAD

AREA B 2.15 x Q;

AREA C WIND 2.6 x Q, SPEED m/se<

258 309 43.6

224 270 40.8

215

187

155

133

105

90

260 4o.u

226 37.2

187 34.0

161 31.6

CLADDING LOADS I

ROOF LOADS - DOMINANT OPENING IN WINDWARD WA1,L

Local pressure factors mJSt not be rlsed in the determination of tile total forces on a structure or a surface srtch as a wa.ll or roof.

Table V.1 DESIGN LOADS - ZONE C - PITCH >20"

.

Qz = P, =

PI =

Ps =

DIAGRAM OF PRESSURE COEFFICIENTS (to be multiplied by Qz)

STRUCTURAL LOAD P, = Q, (PI + P,)

CLADDING LOADS P, = Qz (K x P, + PI)

I I

TERRAIN ATEGORY / HEIGHT 1 PRE;;uRE

I I I

’ I 10 m. 119

5 m. 104 I I

21 10 m. 100

5 m. 87 I I

3 10 m. 72

5 m. 62

4 10 m. 49

5 m. 42

AREA A - Ps + PI

AREA B - 1.5P,+ PI

AREA C - 2.0Ps+ PI

STATIC WIND PRESSURE

DESIGN PRESSURE

INTERNAL PRESSURE

EXTERNAL SUCTION

DESIGN LOADS - Kgf/m* I

AREA A 1.5 x Q,

-

179

156

150

131

108

93

74

63

! STRUCTURAL LOAD

AREA B AREA C WIND 1.85 x Q, 2.2 x Q, SPEED m/set

220 262 43.6

192 229 40.8

185 1 220 / 40.0 /

161 191 I

37.2 I

1

ROOF LOADS - DOMINANT OFENING IN WINDWARD WALL

* Local pressure factors must not be used in the determination of the total forces on a structure or a surface such as a wall or roof.

102’ 104’ 106’ 108’ 110’ 112’

ZONE A 60 m/set 216 km/h

ZONE B 50 m/set 180 km/h

ZONE C 40 m/set 144 km/h

ZoNE -itttl IP Kilometres 0 100 200 300

I’““‘“‘: I km.

24’

22’

20’

18’

16’

14’

12’

10’

3’

UNESCO REPORT-JULY 1987-CYCLONE CONSTRUCTION

Figure V.l PROPOSED WIM) ZONES FOR VIET NAM

74

._ . .

PROPOSED WIND FORCES FOR VIET NAM TERRAIN CATEGORIES - ROUGHNESS OF SITE

TERRAIN CATEGORY 1 EXPOSED TO THE WIND FROM THE SEA

. OR ON HIGH EXPOSED HILL

WIND )

SEA . * . . . .- . -, ;. . . . . * . . w..., . . . . . -. . . .- -: : . . . . . . * : . . . : .* : . . . * : .*, . . . . . . . . . . .*:* . .., . 1. .

, .‘~.‘;-‘:.*. . . ::*.-* . . . . . , . . , * k -*. * . * .

TERRAIN CATEGORY 2

DATUM OPEN COUNTRY ADJACENT AIRPORT OR PADDY FIELD

> WIND

TERRAIN CATEGORY 3 SHELTERED AREAS

SUBURBS AND NEAR WIND HEAVY TREED AREAS

TERRAIN CATEGORY 4 HEAVY DENSITY AREAS-CITY CENTRES

* w ~~~ W’ND ) . . . . . . - . ** . . . . :*: . . . - .a.. * - :.:*.

. * ..I - , .* * . . *. . . ’ : . : .*.. . . *. . . ‘, . . ** ,- * . *b *. . . .

Figure V.2 DIAGRAM OF TERRAIN CATEGORIES

75

_.-._ ..-- ..-.

~1.5 TOTAL

-4 WIND

5ECTlON - ROOF PITCH > 20”

= 1.7 -fOTAL

WIND 3 t SECTION - ROOf PITCH ( 20”

1.4 JOTAL

+ = INTERNAL PRESSURE

- = EXTERNAL SUCTION

+ O&+(-0.9) = 1.7 OUTWARDS

+0.8+(-0.7) = 1.5 OUTWARDS

+ 0.8 +(-0.6) = 1.4 OUTWARDS

Figure V.3a STRUCTURAL LOAD COEFFICIENTS, INTERNAL AND EXTERNAL PRESSURE - Dominant opening on windward side - internal pressure + 0.8

0.9 -KJTAL

SECTION - ROOF PITCH ) 20”

1.1 TOTAL

WIND

SECTION - ROOF PIKId ( 20e

WIND

t = INTERNAL PRESSURE

- = EXTERNAL SUCTION

+0.2+(:-0.7) = 0.9 OUTWARDS

+ 0.2 +(-0.9) = I.1 OUTWARDS

+ 0.2 t (-0.61 = 0.8 OUTWARDS

Figure V.3b STRUCTURAL LOAD COEFFICIENTS, INTERNAL AND EXTERNAL PRESSURE - Openings on opposite walls - internal pressure + 0.2

77

NORMAL FftESSURE 1 CORNER4 I

. . PRESSURE 1

ISOMETRIC OF BUILDING

IP. INTERNAL PRESSURE MAXIMUM - 0.8 x Force

EP. EXTERNAL PRESSURE MAXIMUM - 0.9 x Force

"K" FACTORS ARE CLADDING ONLY

1.0 GENERAL AREA A x EP. + IP.

1.5 PERIMETER AREA B x EP. + IP.

2.0 CORNER AREA C x EP. + IP.

Figure V.4 LOCAL PRESSURE FACTORS - To be applied to cladding loads only

78

VI. SUP%IARY OF CONCLUSIONS

The workshop and training course covered a wide variety of issues. While the project aims to develop a prototype design, it has been noted that here are many aspects to constructing educational buildings which can resist damages by typhoons. Some of the problems can be dealt with through technical actions but many other require action by administrators in the Ministries of education and construction at central provincial and district level.

In appendices 8 and 9, respectively, are summaries of all the points made during the workshop and the training course. These records show the active participation by both technical and administrative personnel from central government and the provinces. The conclusions which were reached in these five days of discussions are summarized below. For a full under-. standing of their context, the annexes should be consulted. The conclusions are assembled under three headings: technical; research and development; and administrative.

Technical

1. Wind zones must be established for the entire country. Based on available data, an interim zoning has been suggested.

2. Wind loads on buildings need to be established. Based on available data, an interim code for wind loading has been suggested.

3. Coefficients for wind load distribution need to be used to calculate the requirements for each building dependent on its size and location. Coefficients for cladding loads should also be applied. A full set of coefficients has been suggested.

4. Engineers need to understand the theory for designing buildings subjected to external and suction forces created by strong winds. This includes the need to follow a continuous chain of forces from the roof down to the foundation. This theory has been taught to the participants.

5. Local materials such as brick, timber and bamboo can perform satisfactorily in high winds if they are adequately fixed and the building structure as a whole hz integrity. A dialogue was begun on how this could be accomplished.

6. The most critical need is to have fixings which are strong in tension and can tie down the various building components (see section on R & D),

7. Good site planning and appropriate landscaping can substantially improve the chances of a school building to survive a typhoon. Basic principles have been established for selecting sites and for planting hedges and trees.

8. The failures of weak doors and windows can initiate the destruction of buildings. Improved hardware should be used and better installation procedures adopted.

79

9. Air leaks on one side of the building only should be prevented.

10. Reinforced concrete ring beams should be used at the tops of external walls.

11. Long exterior walls should have strong supports in between transversal walls to resist overturning.

12. Building materials should be selected which will be low in maintenance needs. Sub-standard materials should not be accepted for educational buildings.

13. Construction should be supervised by experienced and knowledgeable technical personnel who understand the nature of forces which a typhoon places on a building.

14. Cost planning should be introduced to compare the cost of various design approaches.

Research and Development

1. A systematic study should be made of the problems being faced in order to identify all local research and development needs.

2. Single layers of tiles will inevitably lift up in typhoon speed winds, thus tile manufacturers need to develop tiles which can be securely attached to battens.

3. Sheet roofing is more easily secured than tiles and also uses less timber. Manufacturers need to develop new roofing types based on materials available in Viet Nam.

4. Galvanised steel strap fixings and tile clips need to be broadly applied. These can be manufactured in Viet Nam with some external assistance. Possibly these could be manufactured as a part of the programme to link education and work.

Administrative

1. A continuous chain of administrative responsibility for the creation of typhoon resistant schools needs to be established. This chain will stretch from central level to provincial to district to community and will include both educational administrators and technical personnel responsible for construction.

2. Public awareness needs to be intensified. In particular the public needs to understand that many local materials can effectively withstand typhoons if they are correctly used and the buildings are regularly maintained. School teachers and school directors have important roles to play in such a campaign. Strongly built schools may be designated as post disaster centres.

3. School buildings need to be places where learning can take place.

effective teaching and School directors and teachers need to see

80

that classrooms are of an adequate size, satisfactorily equipped and provided with adequate natural light and ventilation. Furniture and equipment should not be damaged by typhoons. These criteria can still be respected in school buildings constructed to resist typhoons.

4. Existing educational buildings need to receive good maintenance. Periodic maintenance programmes should be scheduled for every educational building with those in wind zone 1 receiving first priority.

5. Existing educational buildings should be strengthened to a standard where they will suffer only minor damages by typhoons. Steps to be taken include introducing steel straps to tie together all roof members, a tie beam at the tops of walls and a steel tie from the trusses to the foundation. Educational buildings in wind zone 1 should receive first priority. This will involve rebuilding the roofs. A satisfactory method for attachment of tiles to battens has not yet been developed (see research and development above).

6. A rigorous programme to landscape school compounds is needed. This can be related to the educational activities of each school.

7. The results of the above activities needs to be recorded and circu- lated to all officers concerned and to the village authorities who are responsible for school building construction and maintenance.

81

-...

VII. FUTURE ACTIONS UNDER THE PROJECT -

The planning calendar for the project for typhoon resistant schools in Viet Nam is given on the following page.

The project has completed the first phase of activity which was the field survey and holding of the national training course.

The next responsibilities of the government will be to prepare preliminary designs of the prototype buildings based on their previous work and the suggestions made during the workshop and seminar. It is planned that these prototype designs will include two building types e.g. i) a new building and ii) the remodeling of an existing building. Upon receipt of these designs and their approval, UNESCO will pay the second installment of the current contract and under the UNESCO-AGFUND project and order materials for the prototype construction with the cost not to exceed US $10,000.

The construction will take place during early 1988. The government aims to construct prototypes in wind zone 1 areas of the seven provinces which attended the workshop/training course. They will be inspected by the UKESCO consultant Mr. Kevin J. Macks in May. A one week mission in Viet Nam is foreseen. The inspection should take place when the prototypes are in the stage between the pouring of the ring beam and attachment of the roof battens.

As the prototypes will be located the full length of wind zone 1, it is expected that several will be in or near to typhoons in the 1988 season. Following this testing under real conditions, the MOE and UNESCO will make an evaluation of the project and recommend what changes, if any, might be made in the designs and administrative procedures.

The recommended designs will be communicated to all the concerned provinces through training and a small pamphlet which will be provided to at communities and school level. An additional $4,000 is available under the UNESCO-AGFUND project to support these activities.

Meanwhile, UNESCO will, based on the data collected during the workshop and training course and on the prototype designs, prepare a short report for potential donors identifying a project for developing national self reliance in making classrooms in Viet Nam resistant against typhoons. This project proposal will be prepared by September 1987 and will emphasize the reinforcement of existing educational building structures. It will include the provision of already manufactured fixings and reinforcement in the initial stage and the development of Vietnamese capacity to produce these fixings in the subsequent stage.

i’! - u

83

Project for typhoon resistant schools in Viet Nam: Planning Calendar

Action July 86 Jan 87 July 87 Jan 88 July 88 Jan 89

I I I I I

Govt. request Unesco identification mission

Govt. draft design proposals

Unesco technical advisory mission and national training

UNESCO contacts with donors to enlist support for implementation on large scale

Site identification

Prototype designs

Approval by UNESCO

Materials delivery Construction

Inspection by KJM Unesco consultant

Typhoon season

Evaluation by SRV/ MOE and UNESCO

Dissemination of technical brochures to communities

34

Appendix 1.

SUMMARY OF OPENING STATEMENT BY MINISTRY OF EDUCATION

At the Seminar on "Design of Low Cost Schools" held in Hanoi in September 1981, SRV Ministry of Education reached an agreement with international organizations: UNESCO/PROAP and UNICEF on a Programme of Co-operation for a research on maximum and minimum norms of school and kindergarten as well as typhoon resistant schools development.

In implementation of this agreement, UNESCO/PROAP has maintained a continuous co-operation with SRV Ministry of Education in the development of educational buildings. Mr. J. Beynon has been to Vietnam on many missions and has contributed valuable recommendations to schooi development for architects of Ministry of Education.

Following the Training Course on educational buildings in cyclone affected areas which took place in Manila, Philippines in March 1986, this Seminar on typhoon resistant school development funded by UNESCO/PROAP will have a great impact and contribute a great deal to transferring knowledge and experience to Vietnamese specialists in school development.

May 1, on behalf of participants at the Seminar, express our sincere thanks to UNESCO/PROAP for their valuable financial and technical assistance rendered to our typhoon resistant schools development programme. Our thanks also go to Mr. J. Beynon and Mr. K.J. Macks for their assistance and recommendations.

Dr. Tran Xuan Nhi Vice-Minister of Education

85

Appendix 2.

SLLMMAHY OF OPENING STATEMENT BY LTNESCO -

Unesco has been involved in construction of educational buildings in Viet Nam since 19.72 when a number of schools were constructed with UNICEF financial assistance and UNESCO advise on design. It was through this involvement that UNESCO has become aware of the damages which occur to educational buildings located on the coast of the Northern Provinces of the country.

In UNESCO's 1983-89 medium Term Plan priority has been given to the problems of educational buildings in areas affected by natural disasters including earthquakes and typhoons. Thus two regional training courses have been held on the subject of educational buildings in typhoon affected areas (Fiji, April 1985; Manila, May 1986). In additional technical advice has been given to Tonga, Philippines, and Bangladesh, these being countries which have experienced the substantial destruction of schools by cyclones.

In the case of Viet Nam, Unesco has been able to obtain a limited mount. of funding to support a research and development project for the construction of one or more prototype educational buildings in Viet Nam. LNESCO) however, is not a donor agency and therefore is unable to finance large scale projects as these are the responsibility of governments. Nonetheless external donors can be sought and they might be interested to provide the small critical elements which can serve to improve local materials so that they can perform satisfactorily in strong winds. However, if external assistance is to be found, it can only be on the basis that this assistance will lead to Viet Nam's eventual self reliance to produce these initial elements which, in the first instance may be provided through external donors.

One way in which Unesco assists countries is to provide for the exchange of experiences between countries. In this case UNESCO has brought a consultant, Mr. K.J. Macks, an architect from Townsville, Australia, who has had more than 20 years of experience in constructing buildings in the cyclone affected areas of northern Australia and who is chairman of the James Cook Cyclone Structural Testing Station. He is therefore fully conversant in the development and use of building materials which can resist cyclone force winds.

LJNESCO is most pleased to continue its cooperation with Viet Nam for the construction of buildings which are suitable places for children and adults to learn. We all hope that as a result of this current activity we will be able to find a solution for educational buildings in typhoon affected areas which will be strong enough to resist the storms yet economical enough to be built on a large scale.

John Beynon Acting Deputy Director uN.DSCO, Bangkok

86

Appendix 3.

Wed. 10 June

Thu. 11 June

Fri. 12 June

Sat. 13 June

Sun. 14 June

Mon. 15 June

Tue. 16 June

Wed. 17 June

Thu. 18 June

Fri. 19 June

Sat. 20 June

K.J. Macks

K.J. Macks

K.J. Mucks J. Beynon

K.J. Macks J. Beynon

K.J. Macks J. Beynon

Unesco team S.R.V. team

Unesco team S.R.V. team

Unesco team S.R.V. team

Unesco team S.R.V. team

Unesco team S.R.V. team

ITINERARY

Townsville - Singapore

Singapore - Bangkok Technical briefing Unesco, Bangkok. Discussion with public information officer.

Technical preparation for mission. Meeting with Assistant Director General, UNESCO.

Review of UNESCO documentation on earthquake design.

Day off.

a.m. p.m.

a.m.

p.m.

a.m.

p.m.

a.m.

p.m.

a.m.

p.m.

a.m.

p.m.

Airport check-in. Bangkok - Hanoi

Visit to Ho Chi Minh mausoleum and to war museum. Planning meeting at the Ministry of Ed.

Hanoi- Thai Binh, Thai Binh province. Meeting with provincial officials. Visit to Chua Keo temple. Meeting with Provincial officials.

Travel to Tien Hai District. Orientation by Tien Hai District officials. Visit to Dong Quy Basic General School (BGS) Visit to Dong Xuyen BGS Visit to Dong Tra BGS Visit to Dong Hoang BGS Visit to Dong Lam BGS Visit to Dong Co BGS Travel to Nam Dinh, Ha Nam Ninh province. Reception by provincial officials.

Meeting with provincial officials. Travel to Xuan Thuy district. Orientation by District officials. Visit to Xun Tuay Secondary School CSS). Visit to Huyanh Son BGS. Visit to Giao Ha BGS. Visit to Tho Nghiep BGS. Visit to Xuan Vinh SS.

Visit to Tran Pagoda & Phu Ninh Tower. Visit to Nguyen Van Troi BGS (UNICEF aided, 1979). Meeting with provincial officials. Nam Dinh - Hanoi.

87

Sun. 21 June

Mon. 22 June

Tue. 23 June

Wed. 24 June

Thu. 25 June

Fri. .26 June

Sat. 27 June

Sun. 28 June

Mon. 29 June

Tue. 30 June

Wed. 1 July

Thu. 2 July

Fri. 3 July

Sat. 4 July

Unesco team

Workshop participants

J. Beynon Workshop participants

Course participants

Course participants

Unesco team

Workshop and course participants

Course participants

Unesco team Steering committee

Unesco team SRV team Steering committee

Unesco team SRV team

Unesco team SRV team

Unesco team

Unesco team

Unesco team

Unesco team

Unesco team

K.J. Macks

a.m. p.m.

a.m. p.m.

a.m.

p.m.

a.m. p.m.

a.m. p.m.

p.m.

p.m.

a.m. p.m.

p.m

a.m.

p.m.

a.m.

p.m.

a.m.

p.m.

Preparation of report on field trip and sketch designs for discussion in workshop.

Workshop on typhoon resistant schools development.

Meeting with UNICEF. Workshop continued. Workshop continued.

Workshop continued. Workshop continued.

Training course on typhoon resistant schools development.

Meeting with UNDP.

Reception by J. Beynon and K.J. Ma&s.

Training course continued, Training course concluded.

Meeting at Australian Embassy. Dinner hosted by H.E. Minister of Ed.

Visit to educational equipment factory and MOE ceramics factory. Evaluation of course and preparation of future actions.

Visit to Hai Phong Province.

Tour of Ha Long Bay.

Ha Long - Hanoi.

Report on activity to Deputy Director DIC/MOE. Hanoi - Bangkok.

Report writing.

Report writing.

Report writing.

Report writing.

Bangkok - Townsville.

88

Appendix 4.

LISTS OF NAMES

A. Key officials contacted

Ministry of Education:

- H.E. Dr. Pham Minh Hat, Minister. - Dr. Tran Xuan Nhi, Vice-Minister. - Mr. Nguyen Chi Linh, Director, Department for International

Co-operation. - Mr. Le Nang An, Deputy Director, Department for International

Cooperation. - Mr. Nguyen Dinh Phung, Acting Director, Department of Educational

Buildings.

UNDP:

- Mr. Sietse van der Werff.

UNICEF:

- Mr. Steven Allen, Programme Officer. - Ms. Danielle Vuianovith, Programme Officer.

Australian Embassy:

- Mr. Sean Kelly, Second Secretary.

B. Persons involved in field trip

1. UNESCO team:

Mr. K.J. Macks, architect, Macks and Robinson Pty. Ltd., Queensland Mr. J. Beynon, Principal Architect, UNESCO, Bangkok

2. SRV team:

Mr. Nguyen Dinh Phung, architect, Acting Director, Department for Educational Buildings.

Mr. Nguyen Huu Chinh, engineer in charge of construction planning. Mr. Huyuh Cong Thuy, expert, Dept. of International Cooperation. Mrs. Duong Van Thanh, expert, Dept. of International Cooperation (Hai

Phong province, visit only).

3. Hanoi:

Mr. Nguyen Chi Linh, Director, International Cooperation Department. Mrs. Duong Van Thanh, Specialist, International Cooperation Department. Mrs. Hoang Phuong Thao, architect, Dept. for Educational Buildings.

89

C. List of participants in workshop and training course

4. Thai Binh Province:

Mrs. Dao Thi Nhat, Vice President, People's Committee in charge of Education.

Mr. Tran Hung, Secretary to V.P. People's Committee in charge of Ed. Mr. Nguyn Dinh Chu, Director of Education services. Ms, Nguyen Sinh Chi, Deputy Director of Education services. Mr. Nguyn Thanh Cam, Deputy Director of Education services. Mr. Vu Dinh Thuong, International Liaison Officer. Mr. Phua Va Te, Head of finance and planning. Mr. Khong Vu Con, Officer of Administrative Bureau. Mr. Nguyen Ngoc Lam, Head of Commission for Construction.

5. Tien Hai District:

Mr. Hoang Xuan Thien, President People's Committee. Mr. Vu Dinh Quy, Director of Education. Mr. To Phuong Ngai, Member of the secretariat, People's Committee.

6. Ha Nam Nih Province:

Mr. Lai Van Thu, Member, People's Committee. Mr. Phan Ngoc Huyen, Director of International Affairs. Mr. Ngyun Cong Son, Director of Education. Mr. Nguyen Due Vinh, Deputy Director of Education. Mr. Phan Ngoc Canh, education specialist of the People's Committee. Mr. Ngoc Khue, specialist in construction. Mr. Mai Hong Bang, officer responsible for school construction.

7. xuan Thuy District:

1Mr. Mr.

Vu Tuong Thang, Vice President, People's Committee. Ngyuen Chi, Director of education.

I) Ministry of Education: 1. *Dr. Tran Xuan Nhi, Vice Minister 2. *Mr. Nguyen Chi Linh, Director, DIC 3. *Mr. Nguyen Dinh Phung, architect, Director, DEB 4. Mr. Nguyen Huu Chinh, building economist, in charge of

construction planning, DEB 5. Mr. Nguyen Canh Chi, architect, DEB 6. Mrs. Hoang Phoong Thao, architect, DEB 7. Mr. Nguyen Liem Chinh, architect, DEB 8. Mr. Ngo Quang Dung, architect, DEB 9. Mr. Luong Thi Yen, architect, DEB

10. Mrs. Dong Doan Trang, engineer, DEB 11. Mr. Do Huy Hung, engineer, DEB 12. Mrs. Duong Van Thanh, engineer, DEB

t Steering committee member.

90

.

II) Ministry of Construction, Institute of Housing and Public Building Design: 1. Mr. Nguyen Tan Van, architect, Director, Dept. of Design 2. Mr. Hoang Vinh Thang, engineer, Deputy Director, Dept. of Desigh

III) State Commission for Construction: 1. Mr. Le Quang Huy, engineer, Deputy Director 2. Mr. Nguyen Van Pho, MA/structure, Specialist 3. Mr. Nguyen The Viet, MA/structure, Specialist

IV) Hai Phong: 1. Mr. Ngo Rat, BA/TTC, Deputy Director of Education (Provincial) 2. Mr. Dinh Van Giap, MA, Provincial Committee for Construction

V) Nghe Tinh: 1. Mr. Phan Huy Dinh, BA/TTC, Deputy Director of Education 2. Mr. Mai Wan Can, BA/TTC, Deputy Director, Committee for

Construction (Provincial)

VI> Ha Nam Ninh: 1. Mr. Nguyen Due Vinh, BA/TTC, Deputy Director of Education 2. Mr. Mai Hong Bang, BA 3. Mr. Dinh Dinh Phung, engineer, Committee for Construction 4. Mr. Nguyen Chi, BA, District Director of Education

VII) Thai Einh: 1. Mr, Nguyen Dinh Chu, aA(adm), Director of Ed. (Provincial) 2. Mr. Tran Dinh Quy, engineer, Director of Construction Committee 3. Mr. Nguyen Ngoc Lam, engineer

VIII) Hai Hung: 1. Mrs. Nguyen Thi Dung, BA/TTC, Deputy Director of Education

IX) Binh Tri Thien: 1. Mr. Truong Si Tien, RA/TTC, Deputy Director of Education

X) UNESCO: 1. *Mr. John Begon, Acting Deputy Director, PROAP 2. *Mr. Kevin J. Ma&s, Consultant Architect

. * Steering committee member.

91

Appendix 5.

SCHEDULE OF REPORTS PRESENTED AT WORKSHOP AND TRAINING COURSE -- ----

1. Introduction of participants

2. Official opening and address

3. Response from UNESCO

4. Report No. 1

5. Video of cyclone damage

6. Report No. 2 -. Design

7. Report No. 3 - Structure

8. Report No. 4 - Thai Binh

9. Report No. 5 - Ha Nam Ninh

10. Report No. 6 - Hai Phong

11. Report No. 7 - Hai Hung

12. Report No. 8 - Nghe Tinh

13. Report No. 9 - Binh Tri Thien

14. Report No.10 - Commission for construction

15. Report No.11 - UNESCO

: Mr. Nguyen Huu Chinh, MOE.

. . Vice-Minister of Education, Dr. Tran Xuan Nhi.

: Mr. John beynon.

: Mr. Nguyen Dinh Phung, MOE.

: Mr. K.J. Macks.

: Mr. Do Huy Hung, MOE.

* Mrs. Dang Doan Trang, DEB. .

: Mr. Nguyen Dinh Chu, DOE.

: Mr. Nguyen Due Vinh, DDE.

: Mr. Ngo Bat, DDE.

: Mrs. Nguyen Thi Dung, DDE.

: Mr. Phan Huy Dinh, DDE.

' Mr. Truong Si Tien, DDE. .

: Mr. Le Quang.Huy, DD.

* Mr. J. Beynon. .

16. Report No.12 - UNESCO : Mr. K.J. Macks.

92

Appendix 6.

SCHEDULE OF PAPERS PROVIDED BY MOE -

A. At workshop

1. Report by Ministry of Education "Construction of schools in typhoon affected areas".

2. Report from Nghe Tinh Province on damages.

3. Report from Ha Nam Ninh Province on damages.

4. Report from Hai Phong Province on damages.

5. Report from Thai Binh Province on damages.

6. Verbal reports ere presented from:

(a) Hai Hung Province (bj Binh Tri Thien (c) State Commission for Construction Cd) Ministry of Construction

B. From other sources

1.

2.

Assessment in the long term for the construction of cyclone resistant housing in Binh Tri Thien Province. UNCHS mission report, April 1985 by Bob Hardy, Habitat.

It.IDP draft report "Disaster preparedness and rehabilitation in Rinh Tri Thien Province".

C. Technical information

1. From meteorological station "Plots of tracks of cyclones crossing Viet Nam 1976 - 1985".

2. Chart of estimated wind speeds. Wind levels, 6 to 13. - 50 kmjhr to 150 km&. Formula to convert wind speed to pressure - code.

3. Educa%ion in Viet Nam - Booklet 1982. Booklet describing Education facilities, training and development.

4. Photos of damage, Nov. 1982, Cyclone No. 7.

93

Appendix 7.

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

SCHEDULE OF PAPERS AND MATERIALS PROVIDED BY UNESCO

6 sets of drawing materials and pen sets

30 copies of Manila training school papers

3 copies of Bound Manila papers

1 copy - CBRC papers 1973

1 copy - CBRC papers 1981

1 copy - Australian wind code 1170 - 1983

1 copy - Sri Lanka design manual 1979

Copies BDRI - Aust. - Notes ZlA, 218, 21C. Design of brick walls and design tables

5 copies Design of guide for secondary schools in Asia

Cyclone Testing Station - Australia 1 copy Technical Reports Nos. 10, 15, 20 - ceilings 1 copy Information Bulletins - Blockwork house

5 copies Cyclone resistant rural primary school construction by UNESCO - A design guide

5 copies "Typhoon" - Construction of typhoon resistant buildings, Asian Regional Institute for School Building Research, Colombo , 1972

40 copies of photographs of damages inspected

Two Video-tapes were presented to the Vice- Minister describing cyclone damage in Australia and corrective measures adopted

Full set of working drawings of State High School at Collinsville, Queensland, Australia, with compliments of the Queensland State Works Department

Copies of this report provided to each participant and authorities

----_----------------------------------------------------

In addition approximately 70 black white and 50 colour photos were taken for information.

Also some 63 other technical books and reports were taken and placed on display for the period of the mission. They were widely read.

94

: PROAP

: PROAP

: KJM

: KJM

: KJM

:KJM

:KJM

:KJM

* PROAP .

: KJM * KJM .

: PROAP

: PROAP

: PROAP

: KJM

:KJM

: KJM

Appendix 8.

SWY OF WORKSHOP DISCUSSIONS

Monday, 22 June 8.00 - 8.20 - Steering Committee : Discussions with Mr. Tran Xuan Nhi,

Vice Minister of Education and Mr. Nguyen Chi Linh; Director DEB and others.

8.20 - 8.25 - Opening of proceedings : Chairman Mr. Nguyen Chi Linh.

8.25 - 8.30 - Opening address by Mr. Nguyen Yen Huu Chinh, Engineer in charge of Cost Planning, DEB. who introduced the partici- pants.

8.30 - 8.50 - Opening address by His Excellency Vice Minister of Education, Mr. Tran Xuan Nhi, who officially opened the workshop, welcomed Unesco consultants and participants and gave overall details of storm damages from 1977-1985 and discussed developments with UNESCO and UNICEF from 1981. Participants came from 7 provinces and were made up of architects, engineers and directors and deputy directors of education plus representatives from the Ministry of Construction.

8.50 - 9.10 - Mr. J. Beynon, Acting Deputy Director, UHESCO, responded to the welcome and summarized UNESCO ongoing involvement in school development, including provision of cyclone protective construction advice which had been given in Fiji and Manila and that his team was here to assist Viet Nam in this field. Mr. Beynon introduced Mr. K.J. Macks, consultant architect from Australia who was experienced in cyclone research and practical construction.

9.10 - 9.20 - Morning tea - Steering Committee : Discussions with Vice Minister.

9.20 - 10.00 - Report No. 1 by Hr. Nguyen Dinh Phung on behalf of Department of Education. He described the type of construction damage, described quality of materials, his exay‘ination of damages and proposals prepared by his staff to overcome the problem. A detailed research paper "Construction of schools in typhoon affected areas (32 pages)" was handed out. (see Chapter III)

10.00 - 10.30 - Short address by K.J. Macks who presented a 20 minute video of the damage caused by Cyclone Tracy in Darwin in 1974. Showed slides of chain of connection and failure modes.

10.30 - 10.40 - Recess

10.45 - 11.30 - Report No. 2 by Mr. Do Huy Hung, DEB, giving more detailed descriptions of the recommendations of the

95

Ministry of Education and advising on quantities of permanent, semi solid, and temporary classrooms, details of site planning principles and landscaping, fences and size of classrooms, existing and proposed at 37 m2. Reference was made to numerous well presented plans, details and diagrams on display boards to illustrate the situation including proposed method- of construction. (see Chapter III)

11.30 - 13.30 - Lunch

13.30 - Opening of session : Chairman Mr. 3. Beynon.

13.30 - 14.30 - Report No. 3 by Mrs. Dong Doan Trang, engineer DEB, describing in detail, supported by additional display diagrams, design loads, design theory and calculations investigating engineering design proposals for schools including details of materials and fixing methods. (see Chapter III)

- Described wind movement and scale of forces with winds of 150 km/hr gusting to 180 km/hr with loads of 110 kg/m2 at Thai Binh and Ha Nam Ninh provinces in storm No. 5 of 1986.

14.30 - 15.00 - Report by UNESCO by Mr. J. Beynon who spoke on size of classrooms, design for lighting and ventilation and Unesco proposals for participation in the project.

15.00 - 16.15 - Report by Consultant Mr. K.J. Macks, thanking Unesco and Viet Nam for opportunity to visit and assist in recon- struction technique. Referred participants to Library of technical literature (63 volumes) brought over for them to examine. Spoke of opportunities at workshop to share experience to completely understand the problems of high wind forces. Impressed by preparations work and techni- cal details prepared by Viet Nam, DEB, MOE. Advised participants to take careful note of professional advice. Suggested more accurate anemometer recordings at critical coastal areas be developed to withstand and record wind speeds. Advised participants to take note of following points.

a) General planning and thinking

- Know your country, typhoon areas and character of wind.

- Take care in site selection near hills, trees and mounds.

- Carefully plan site to avoid severe loads on buildings.

- Study general building design. - Examine problems with existing details. - Think out continuity of fixing. - Develop upgraded details of corrections.

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- Think about the uplift forces created by wind. - Consider extra strength offered by installation of

good ceiling. - Carefully consider total length of classroom blocks. - Avoid hook bolts and roof tiles. - Plan and maintain good landscaping with wind holes in

foliage of min 20% to reduce loads on trees and hedges and to maintain ventilation.

b) Engineering matters and details of connections

- Advised against flat or steep roof slopes. - Recommended slopes between 25 - 30' - Examine ridge details. - Examine purlin and roof cladding fixings. - Criticised small size of battens and rafters. - Examine size of top plates on walls. - Consider locating trusses at closer centres. - Always place truss against gable brick wall. - Instail concrete tie beam to perimeter of tops of all

brick walls and tie down to foundations. - Plan for vertical bracing between trusses preferably

at l/3 points. - Plan for bracing in plane of roof. - Consider corner ties at 45" across corner fixed to

top plates.

c) General matters

- Spend more time to understand terrain categories. -t Check height of buildings and roof shape. - Check wind forces and coefficients at turbulent

areas. - Check self weight of brick, tiles, timber and other

materials. - Avoid making trusses too steep with consequent high

roof which attracts greater overturning load and stress at ridge.

d) Presented series of diagrams to illustrate design theory and practical structural support and fixing -_ of small members -

- Dien Bien Phu diagram of ring beam principle. - Ho Chi Minh trail diagram of vertical integrity. - Concrete frame of foundation beam, concrete columns

and ring beams to strengthen building and make planning more flexible and to reduce reliance on brick walls.

- Examples of small metal and steel connectors. - Sample sketches of fixing of roof truss to ring beam,

of fixing truss members, and of fixing purlins to trusses.

- Importance of bracing in all directions.

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e) Responsibilities of educators in schools

- Give brief talks to small children about connections of arms and legs to body.

- Teach elder children about how their school is held together.

- Improve curricula for trade courses in schools. - Develop construction technology sohools of high

standard. - Develop better training of trade teachers. - Send teachers to refresher courses or seminars. - Get teachers to look at research projects. - Develop basic knowledge of construction principles

at director, deputy director and at school administrator level.

f) Education in building colleges

- Select experienced personnel to head technical school training.

- Hold annual or bi-annual workshop over next 5 years to understand cyclones and to learn fixing details.

- Talk to builders, engineers, architects.

g) Architects and engineers responsibilities

- Study site selection, site planning and nature and topography of surrounding country environment.

- Examine bracing of roofs with ceiling fixed on the rake (slope) of the roof (to under purlins).

- Change roof cladding to sheet roofing to prevent leaks and to get stronger roof.

- Design small details. - Get involved in all details and fixing techniques. - Talk to builders, colleges, engineers, educators.

h) Responsibilities of Governments

Provide better and more anemometers to record wind speed. Locate at regular intervals along coast and at airport. Sponsor research programmes into materials and other wind studies. Support those involved in research and construction. Revise the National Wind Code.

i) Responsibilities of manufactures of materials -.-_

- Study design of tiles and timbers. - Develop proper details for fixing of materials. - Research creates opportunities to improve products. - Seek advice from architects and engineers.

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j) Research and Testing establishments

- Test roof tiles for wind load resistance. - Test other materials. - Check other research available. - Liaise with other overseas groups such as UNESCO,

Australia, and Philippines re wind problems. - Develop metal brackets or fixing clips and support

local manufacture.

k) Builders and Tradesmen's responsibilities

- Study codes and understand what they say. -) Study general effects of wind action. - Attend seminars. - Support key staff to improve their knowledge. - Listen to architects and engineers. - Talk to architects, engineers and researchers.

Tuesday, 23 June 8.00 Opening of session : Chairman Mr. K.J. Macks.

8.15 - 8.45 Report No. 4 - Thai Binh Province (typed report) by Mr. Nguyen Dinh Chu, Director of Education. - Reported on enrolments, classes, classrooms. - Extent of damage, population densities. - Development since 1954. - Low lying region. - Stiffness in buildings unable to resist cyclones. - Good materials not generally available.

8.45 - 9.30 Report No. 5 - Ha Nam Ninh Province (typed report) by Mr. Xuan Due Vinh, Deputy Director of Education. - Suggested concrete roof to verandah to assist in support. - Recommended tiles be tied to battens. - Connections very important. - Consider over-batten support to roof. - Manufacturers to change mode of making tiles. - Choice of building materials is important. - Materials must have integrity. - Buildings are continually exposed to cyclones. - Cost to country, Govt. has some responsibilities. - We should innovate our way of thinking. - Everything has to be provided by the community. - People pay more attention to their homes than schools. - Need for more community responsibilities. - We must find a solution, we are capable. - Would be good if we could afford ceilings. - Durability and stability very important. - Need to avoid double and treble shifts in classes.

9.45 - 10.45 Report No. 6 - Hai Phong Province by Mr. Ngo Bat, Deputy Director of Education. - Presented damage statistics and report copy. - Requested Unesco participation in school design for each

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of 7 provinces and elsewhere. - 5% of Buildings in province are solid construction. - MOE and SCC should develop Codes and Requirements. - Semi solid construction should be supervised. - Need for specific regulations to suit locality. - Requested discussion on means to resist wind loads. - Mrs. Thang commented on their plan of study of loads,

overturning loads and dead loads.

10.45 - 11.00 Report No. 7 - Hai Hung Province by Mrs. Nguyen Thi Dung, Deputy Director of Education. - Province near Red River away from Coast. - Most problems occur with cyclonic flooding. - 50% of cultivated areas flooded annually for 5 years. - 20 - 30,000 m2 of land lost for cultivation. - Has learnt a lot from workshop. - Will try to apply in province on return. - Need for better site planning. - Will try to reduce CR length from 5 CR length. - They have few doors or windows in schools. - Solutions will be difficult to achieve. - Research into typhoons need to be done. - Lime and thatch ceilings leak and wear out. - Would like prototype of durable classroom.

11.00 - 11.30 Report No. 8 - Nghe Tinh Province by Mr. Dhon Huy Dinh, Deputy Director of Education. - Reported on damage - typed report presented. - Geography and climate unfavourable, winds from Laos. - Poor quality of life - lots of crops destroyed.

- - Natural calamities occur often and quickly. - Explained damages in 1977-78, 1982-83 and 1988. - Displayed good photographic record of storms. - Have instituted some control, better materials,

worknanship. - Need better co-ordination. - 2 Provinces have 170 km of coastline.

13.30 Opening of session : Chairman Mr. J, Beynon

13.30 - 14.15 Report No. 9 - Binh Tri Thien Province by Mr. Trung Si Tien, Deputy Director of Education. - Explained damages on coast 40 km long. - 14. Districts, 11 on coastline. - 1985 storm was 100 year event lasted 25 hours. - All provinces damaged, also ware surge damage. - 80% of trees levelled, D 150 million damage to schools. - Recommended comprehensive document on standards and

supervision, coordination, materials, quality. - Code of Minimum Construction Techniques needed. - They can mobilize people, but need direction. - Guidelines to reinforce existing buildings needed. - Study trees, type, height, spacing for protection.

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14.15 - 15.00 Report No. 10 - State Commission for Construction by Mr. Le Quang Ruy, Engineer, Deputy Director. - Cooperation between MOE and SCC is required. - Storm No. 5 in 1986 and Storm No. 6 told us we need new

approaches and a change in attitude. - Lime brick work is not satisfactory. Maintain low rise

buildings. After this workshop the following must be observed. 1. Reinforce existing buildings - very necessary. 2. Adopt preventative measures and intensity action. 3. People to think of own buildings but also schools. 4. We must close up our schools and prevent leaks 5. Start long term measures now, develop Codes and

Standards. (Old codes may be elementary and out of date.) 6. Set up institute for standardization and Norms in MOE. 7. Block work and brickwork must be strong and monolithic. 8. Use steel or concrete, treat bamboo to improve strength

and life. 9. Reinforce adobe with shells and stones.

10. Maximise existing material use. 11. There are 130,000 classrooms in typhoon areas. 12. Do not repeat mistakes - invest in real schools 13. We must stop, think and consider the solutions. 14. Pay more attention to maintenance and repair that has

often been neglected. 15. Check doors and windows and fixing and hinges. 16. Adopt better principles, community must join in effort. - Offered sincere .thanks to J. Beynon and K. Macks for

visit and work.

15.00 - 15.45 Paper on general principals of educational building design which have relevance to typhoon affected areas : UNESCO, J. Beynon. - Why are we making the spaces? - to learn. - Cyclonic winds create a design problem. - We should solve as many matters as is possible. - Spoke about size of classrooms (refer Asian design Guide). - Adequate window area - 25% of floor area needed 100/300 lux. - Ventilation is vital at the level of the people and at

top of roof to exhaust hot air and to ventilate top of classroom.

- Acoustics are important and no student should be more -- than 7 m from the teacher.

- Flexible spaces and equipment spaces are needed for modern education (note: see Chapter IV for full text).

Wednesday, 24 June 8.00 Opening of session : Chairman Mr. Nguyen Dinh Phung.

8.15 - 8.40 Talk by K.J. Macks. Told story of straw, stick and brick house. Reviewed comments to date and MOE drawings on display. Explained need for brains, integrity and top of wall support. Spoke on overali problems.

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9.00 - 11.30 General discussion and individual summaries

Aj Mr. Tran Dinh Quy --Thai Binh

1. Build only solid 6 x 9 durable classroom and build 10 classrooms in two levels.

2. Develop motto - "People build classrooms" with Govt help - to offer people more pride in schools - each home to help with 3 - 10 kg of rice

to exchange for steel and cement. 3. Try and build 1 or 2 solid durable classroom in each

village. 4. Try next year for 5 villages. 5. Need a design to use. 6. Causes of damages - materials, floods, brick laying,

that&. 7. Classrooms need a ceiling, what kind? 8. Good connections needed. 9. Provide good tree planting.

10. Site planning and site selection important. 11. Site size should be 12 m2 per child. 12. Provision of temporary classrooms needs some priority.

B) Mr. Nguyen Dinh Chu - Thai Binh -

1. Due t.o economy, we cannot build 100% solid buildings. 2. Improvise - some existing classrooms good for temporary

use. 3. They have 81 foundations good enough for 2 level

buildings. 4. Agrees with Vice Minister re 6 x 8 or 6 x 9 CR size. 5. Sheet roofs highly recommended. 6. Aluminium only for temporary use. 7. Connectors, bracing bolts, sheets needed. 8. Use 100 year storm return for design of schools. 9. Schools to serve post disaster function.

10. Requested Unesco help to build 3 schools, 2 on coast.

Cj Mr. Nguyen Due Vinh - Ha Nam Ninh

1. Can develop 3 types of school structures. 2. Temporary use, semi permanent, permanent. 3. Must improve technical materials. 4. Proposes Ministry and Unesco help to find solutions.

D) Mr. Nguyen Van Pho, State Commission for Construction

1. Wants Unesco participation in school design for each of 7 provinces and in some other places.

2. a) Proposed 5 - 30% solid buildings, build 5% each year. b) MOE/SCC must develop codes and regulations. c) Semi solid buildings should be supervised.

20 year programme to complete work.

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.

,

3. MOE/SCC must have strict supervision of solid schools. 4. Must have specific regulations,and specific design for

locality. 5. Will discuss in training school other proposals.

E) Mrs. Dong Doan Thang, DEB

Study loads, overloads and dead loads.

F) Mr. Dhon Huy Dinh - Nghe Tinh

1. Attention should be paid to all kinds of matters. 2. What is to be done with the materials. 3. Ask Government and Unesco what type of materials

available. 4. They are open for technical assistance. 5. they need technical guidance on location, size,

direction, etc.

G) Mr. Ngo Bat - Hai Phong

1. Can we split schools into primary and secondary to make school construction more convenient.

2. Make doors and windows of better materials, improve fixings.

3. Roof to resist leakage and typhoons.

H) Mr. Huy Hung - DEB -

1. Tiles should have holes for better fixing. 2. Select best roof slope. 3. Select landscaping to suit tree heights and spacing from

classroom. 4. Site school on edge of village for protection.

13.30 Opening of session : Chairman Mr. Nguyen Chi Linh

13.30 - 13.40 1) Mr. Dinh Binh Phung, Ha Nam Ninh --.

1. Must respect site planning. 2. School must have ventilation. 3. Trees may reduce lighting. 4. Buttresses for brick walls should be external. 5. Walls should be rendered. 6. Avoid low quality in brick laying and mortar. 7. Must secure doors and windows and use high quality

timber.

13.40 - 13.45 J) Mr. Hoang Minh Thang, State Committee for Construction

1. A research group should be established. 2. There is no research by MOE except damage reports. 3. Results should be disseminated through document or

report.

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4. A manual should be produced, readable by everyone. 5. Consider use of asbestos cement.

13.45 - 13.50 K) Mr. Dinh Van Giap, Hai Phong --

1. Discussed theory. 2. Bracing of buttresses by cables and "deadman" mass

concrete foundation.

13.50 - 14.00 L) Mr. Nguyen Liem Chinh, DEB

1. He has learnt a lot. Hopes to improve with help. 2. Proposes 36 pupil CR: 3. Use timber trusses at closer centres. 4. Use continuous bond beam at 2.0 m. height. 5. Use trees with deep roots and needle like leaves.

14.10 - 14.30 J. Beynon - Report on Workshs - Summary __~ II_- -

1. Promote the slogan "Design it right, Build it right, Keep it right".

2. Teamwork, involving links between: - Communities - District authorities - Provincial authorities - Central Govt. - Unesco - Donors

all five links need to work and to include education and construction components.

3. More detailed work/ideas to be developed to solve problems. - At general administration level. - At Education Administration level. - At mannfacturing level, - With designers. - With Builders.

4. What can Unesco do for villages - is to help them understand:

a) Permanent materials + bad work = temporary building b) Permanent materials + good work = permanent building Demonstrate how a few imported materials e.g. fasteners and door and window hinges can make the transformation.

14.30 - 15.15 K.J. Macks - Summary of workshop

The workshop objectives were: a> To make all personnel aware of the problems caused

by typhoons. b) To become familiar with some of the details to be

avoided.

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c) To be familiar with the type of construction to be followed.

d) To have at director of Education level some appreciation of the theory of construction, the importance of continuity of connections and the importance of the quality and integrity of fixings.

Mr. Beynon and I believe that this has been achieved. The workshop has been very successful. People from different disciplines have sat together, talked and listened. All have learnt something. So all important people should now have a much better knowledge of the problems. Of more importance is the need to establish suitable secure schools. Directors can now see problem areas and know where to go for help. My thanks to His Excellency the Vice Minister for his time, attention and action. Thanks to Mr. Chi Linh for his assistance and cooperation. Special thanks to Mr. Nguyen Dinh Phung for the most excellent presentation and organization. Thanks to Mr. Le Quang Huy for his direct speaking and for his call for action. Thanks to Mr. Phung's associates for the most excellent work in the production of drawings and diagrams and comments. Thanks to all regional directors for their statistical information, reports and for their generous support, and especially to those in Thai Binh and Ha Nam Ninh for their assistance during our field trip. Thanks to all participants for their patience in listening to the technical material, Special thanks to Unesco for giving me the opportunity to attend this workshop. I wish to summarize the key points to be covered in the forthcoming training course.

1. Establish wind zones A.B.C. 2. Determine maximlrun wind speeds. 3. Determine wind forces.

4.

5.

6. 7. 8.

9. 10. 11.

12.

- understand magnitude of forces at different site categories and heights.

Establish Co-efficients: - for walls - at edges and centre. - for roofs - at corner and perimeter and centre. Calculate forces on each member transferring load and on load areas of walls and roofs. Determine critical path of force and resistance. Design joints and select adequate connectors. Check actual quality of timber design, size and connectors to suit timber. Select spacing of timber purlins and trusses. Research stress grade of timber, bricks and nails. Prepare full calculations for one CR block of 3 - 4 classrooms (a) for structure.

(b) for cladding. Develop typical standard details.

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I hope to see well built schools on my next visit. Final thanks to all for the hospitality and assistance and to Mr. Huyuh Cong Thuy (DIC) for his excellent interpreting.

15.15 - 16.00 Dr. Trsn Xuan Nhi, Vice Minister for Education - Conclusions.

Pleased to see the implementation of the project with LWSCO/PRGAP support. Noted the interest shown by the representatives of the provinces and the effective way of holding the meeting with much discussion.

Noted that in the 11 provinces struck by typhoons there are 15 million children enrolled and using 100,000 classrooms. Estimated that 50% of these classrooms have been damaged over the last 10 years. Noted the need to build secure buildings in order to avoid wasting money on reconstruc- tion.

Educational administrators in Provinces and Districts can improve the situation by selecting protected areas for school sites and by organizing tree planting campaigns by the schools.

Classroom size must be realistic and in SRV class attendance is usually from 40 to 70 students. There are now 2.4 million children in grade I which will lead to further problems from growing enrolments. While 30 is an ideal number for the future, the ministry should work on a current figure of 40 to 50. Schools should not exceed 1,300 enrolment as larger schools tend to have loose management. Noted a Vietnsmese saying that "The School is the longest building in the village with no one to take care of it".

Assured the group that the first four links in the administrative chain would be ensured (Community/District - Province - Central Govt - UNESCO) would be maintained.

Stressed the need to use good materials, good management and strong supervision. Participants should communicate what they have learned at the course by holding meetings and courses at provincial, district and village level.

Prototypes will be constructed by the villagers making use of UNESCO's store of technical knowledge. SRV is also counting on UNRSCO to be the catalyst in getting funds from donors. General designs will be produced, but detaiied designs are also needed for different sorts of schools and for furniture.

The need to build these schools as permanent structures. Reminded participants that one story school building can be permanent while 2, 3 or 4 storey school buildings are

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sometimes temporary because of poor workmanship and materials.

Ministry might give consideration to creating separate first cycle secondary schools which is linked to several feeder primary schools. The aim is to eliminate double shifting.

Appreciate technical assistance from UNESCO and looks forward to continued exchange of experience with other countries and help from donors. Accepts the principle that it is best to receive aid for those small building elements such as connectors which are within reach. However, would also appreciate help for glazing and roofing sheets.

Project implementation should be achieved by 1988 in seven provinces with UNESCO experts invited back for evaluation. More research is required. First phase of project is now concluded and counts on those present to realize the second phase which is the prototypes.

On behalf of participants thanks I.XGSCO and calls attention to Vietnamese saying.

To see something is better than to hear it described a thousand times.

To touch something is better than to see it a thousand times.

This, in essence is what the pro.ject for typhoon resistant schools is about.

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Appendix 9.

SUMMARY OF TRAINQiG COliRSE DISCUSSIOR--

Thursday, 25 June 8.00 - 11.30 K.J. Mack - Presentation

- Introduction. - Presented series of 100 slides showing individual damages

caused by Cyclone Tracy at Darwin 1974. - Slides showed every type of failure including failure of

brick work and engineered structures and concrete bond beams not tied down.

- Elaborated on each failure and pointed out causes of failure in each case.

- Descriptions and explanations covered the whole range of topics in .the training course.

- Explained need for good workmanship, good design, good supervision, good inspection, good documentation.

- Showed failure of all types of cladding and reasons for failure.

- Showed failure of Community College with first class materials of brick end concrete but with weak links in the support chain.

13.30 - 14.00 E.J. Macks - Presentation - Spoke on importance of developing wind loads, wind zones

and understanding of site terrain category factors, height factors.

- Discussed importance of understanding cladding loads, local pressure effects, and the difference between structural loads and cladding loads.

14.00 - 15.00 Working session - E.J. Macks and J. Beynon - Divided participants into two groups.

Group 1 - Worked to determine wind zones, wind speeds and forces for Viet Ram.

Group 2 - Worked to develop and understand - Coefficients for structural load force - Coefficients for cladding load forces

All personnel fully participated in discussions.

15.00 - 16.15 Work session - Chairman E.J. Mack - J. Beynon - Groups 1 and 2 continued on their work.

Local group leaders summarized their conclusions to both groups. Agreement by Consensus reached after discussion on:-

a> Zoning Viet Nam into 3 wind zones (1, 2 and 3) and producing zone map of country.

b) Determining design wind speeds for each zone Zone 1 - 55 m/s Zone 2 - 50 m/s Zone 3 - 40 m/s

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.

c? Developed preliminary calculations of free stream dynamic design wind pressures for each zone.

d) Decided to have 4 types of terrain category e.g. ground roughness or exposure terrain categories 1, 2, 3, 4, established.

e) Decided on areas of greater turbulence for cladding forces on walls and roof, established co-efficients.

f) Established coefficients for height of building. g) Converted design loads to forces. h) Developed load tables for all situations.

Friday, 25 June 8.00

9.30

13.30

15.30

- 9.30 J. Beynon - gave summary of matters covered in working group. - Produced wind load tables for 50 yr return wind.

ai Zones 1, 2 and 3. b.1 Site categories 1, 2, 3, 4. c> heights at 5.0 m and 10.0 m. d) Structural loads at 1.0 and 1.7 p, ei Cladding loads at 2.15 and 2.6 p.

- And discussed the Unesco's view of the broad policies for the government.

- 11.00

- 15.313

- 16.20

K.J. Macks - summarized his work and worked out an example of loads on roof framing members. - Also worked out resistance required. 7 Showed capacity of metal connectors. - Calculated size and type of connection to resist load. - discussed dead weight of materials.

- K.J. Macks showed 50 slides of typical technical details which will resist wind loads and types of construction.

- Need to reduce spacing of purlins and trusses to ,reduce load area and design loads on each member.

- Discussed roof slope and principles of overturning moments.

K.J. Macks showed final Video of research and techniques adopted in Australia.

Saturday, 27 June 9.00 Visit to factory making educational equipment.

Satisfied they can make adequate volume of clips, brackets and connectors if steel strip sheet is supplied. Also can be galvanized, but quality to be checked. Other factories in most provinces could also make above items. Visited ceramics factory.

10.30 - 11.00 Final meeting of Steering Committee. - Discussed outcome of course. - Reviewed Vietnam follow-up actions. - Prototypes to include reinforcement of existing building

as well as new buildings.

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,

- Government would hope to build one of each in the seven provinces which attended workshop, making a tot31 of 14 schools by June 1988.

- New schools to be based on design to be sent by MOE. - Reconstructed schools to follow K.J. Macks' proposals. - Clarification of limited Llnesco assistance available for

prototypes. - Suggestion that communities will take more interest if

UNESCO were to provide such materials as roof sheets and glazing.

- Agreement on project planning calendar.

13.30 - la.00 Travel to Hai Phong Province to complete field evaluation of type of construction and extent of general damage and density of population.

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