malawian buildings. - bristol

UK - Malawi Disaster Research Workshop

MUST, 6 -10 August 2018

Malawian buildings.

Materials, Construction techniques and

Deficiencies.

Dr Viviana Novelli, Dr Panos Kloukinas

and Dr Katsu Goda

Day 2: Structural and Earthquake Engineering



It tackles the global challenge of improving the earthquake disaster preparedness

for East African countries by developing integrated earthquake impact assessment

tools in close partnerships with local governmental and academic institutions.



1. How are new masonry buildings designed in Malawi? ➔ code and guidelines

2. How should be (non-engineered) masonry buildings designed? ➔ criteria of the

structural design

3. When are (non-engineered) masonry buildings resistant to earthquakes? ➔

minimum structural requirements for resisting to seismic loads

4. Which are the typical features of the existing buildings in Malawi? How can we

assess the seismic behaviour of the existing buildings in Malawi? ➔ introduction of

the tool FaMIVE (detailed discussion on the tool in Day 5)

5. How can we collect data for existing masonry buildings in Malawi? ➔ inspection form

TOPICS for today..

➔ Organise teams for the field trip for DAY 3



How are new masonry buildings

designed in Malawi?



MS 791-1:2013,“The structural use of masonry – Part 1: Unreinforced masonry walling”.



KARONGA Earthquake - 6-19th December 2009

Four earthquakes of Mw > 5.5 hit the

Karonga region of northern Lake Malawi.



People fleeing from Karonga earthquake (2009)

Relocation triggered by Karonga earthquake (2009)

Over 1000 houses collapsed, a

further 2900 were damaged, 300

people were wounded, and 4 were

killed



Non-engineered masonry constructions



How should be (non-engineered) masonry

buildings designed?



Self-weight

Wind

Earthquake

✓ Strength

✓ Durability

✓ Cost efficiency



When are (non-engineered) masonry

buildings resistant to earthquakes?



The walls lying

perpendicular to the

direction of ground shake

will fail first.

If walls are connected

properly, houses behave as

a box and walls do not

collapse in out of plane.

✓Good connections between walls



This can be achieved by

✓ ensuring good

interlocking of the

masonry courses at the

junctions,

✓ employing horizontal

bands at various levels,

particularly at the lintel

level.



Which are the typical features of the

existing buildings in Malawi?

How can we assess the seismic

behaviour of the existing buildings in

Malawi?



A tool to assess the buildings taking into account

✓ Geometry in plan and in elevation

✓ Roof type

✓ Material type

✓ Structural detailing

✓ Maintenance level

✓ Deficiencies

FaMIVE

Failure Mechanism Identification and Vulnerability

Evaluation method



FaMIVE estimates the seismic

behaviour of masonry buildings

by taking into account the

geometric and structural features

of existing constructions

collected on site by the use of an

inspection form

This approach will be discussed

in details in DAY5



How can we collect data for existing masonry

buildings in Malawi?



Dr. Viviana Novelli

Inspection form FOR HOUSES in MALAWI

1. URBAN DATA

2. GEOMETRY CHARACTERISTICS OF THE FAÇADE (vertical additional are excluded)

3. GEOMETRY CHARACTERISTICS of OPENING

4. GEOMETRY CHARACTERISTICS in PLAN GEOMETRY

5. STRUCTURAL CHARACTERISTICS

6. VULNERABILITY ELEMENTS

7. DAMAGE AND MECHANISMS IDENTIFICATIONS




RELIABILITY:

❑ HIGH

❑ MEDIUM

❑ LOW



Block#: 01

Block#: 02

Salima



Block#: 01

Building#: 01GEO-COORDINATES

Salima 0101S13°47.065' E034°27.128'



Building#: 1

1L

1S

• The form is for single façade.

• At least two facades are

completed for each inspected

building

Salima 0101S13°47.065' E034°27.128'

1L

1L



Type of use:

R=residential;

Co=commercial;

A= administration;

Cu= cultural;

V= vacant;

O=Other

Salima 0101S13°47.065' E034°27.128'

1L100%R 07/08/2018

WORKSHOP TEAM

1L




1. URBAN DATA









M

G: GOOD

M: MEDIUM

L: LOW

50



M

RELIABILITY?

50

H




1. URBAN DATA









SWEXT

EXT: External

INT: Internal



SWEXT

1L

11

2.7m

2.7

No!



SEEXT6

3.7

1S

3.7m

Façade

with gable

X



Dr. Viviana Novelli

SEEXT6

3.7X

1.0

1.0m

L l

Façade

with gable

Gable height

=

L-l



SEEXT6

3.7X

1.0

RELIABILITY?

H




1. URBAN DATA









w

h

4 1.2 1.2 1.2 0.81.7 1.7 1.7 1.8



4 1.2 1.2 1.2 0.81.7 1.7 1.7 1.8

• E2 = openings distributed regularly along the facade

• E1-L (or E1-L C)= one (or more) opening(s) distributed on the left edge of the

facade

• E1-R (or E1-R C)= one (or more) opening(s) distributed on the right edge of the

facade

• C= openings located in central position

• O=other dispositions

• NA=not applicable

E2



4 1.2 1.2 1.2 0.81.7 1.7 1.7 1.8

E2

R R



4 1.2 1.2 1.2 0.81.7 1.7 1.7 1.8

E2

R R

0.73m

0.73



4 1.2 1.2 1.2 0.81.7 1.7 1.7 1.8

E2

R R

0.73

Timber lintel (??) Timber lintel (??) bricks Bamboo lintel (??)

Concrete lintel Concrete band

Lintel type and size

timber post bricks bamboo post

concrete beam concrete ring





4 1.2 1.2 1.2 0.81.7 1.7 1.7 1.8

E2

R R

0.73

If not visible,

You can ask to the

owner, or assume

the type of lintels

but remember that if

the lintel type is

assumed the

RELIABILTY should

be MEDIUM!



Can we assume the type of lintels for this type of house?



4 1.2 1.2 1.2 0.81.7 1.7 1.7 1.8

E2

R R

0.73

This is not the case of the example

in the slides but if the lintel is the

one in the picture

Type: b (beam)

Height: 0.105 X 2 (bricks) +

0.02 (mortar) = 0.230 mm

Material: C (Concrete)

0.23 Cb



4 1.2 1.2 1.2 0.81.7 1.7 1.7 1.8

E2

R R

0.73

NOT VISIBLE

RELIABILITY?

H




1. URBAN DATA









Single skin

Double skin

0.18



0.18

22

3

1L

1S

plan



0.182

2

3

1S

3.7m

6



0.182

2

36

RELIABILITY?

H




1. URBAN DATA







Thatch supported

by a light timber

structure

A1

Typical ROOF TYPE

Corrugated sheets in

light metal supported

by a timber structure

A3

Typical ROOF TYPE



Dr. Viviana Novelli

A3O

1L




A3



1S

A3P




A3



A3O

Unfired bricks

(E)

Fired bricks

(B)

A = stone, B = Fired

brick, C = rubble stone,

D = stones and bricks, E

= sundried brick

(unbunt), F= Hollow

brick.

Note: These need to be

classified in 1= good

quality, 2=medium

quality, 3=low quality



E3

B2

B1

Type and Quality of the

construction material



Dr. Viviana Novelli

A3O

B2



A3O

B2

Unfired bricks

with mud mortar

Fired bricks

with mud mortar

Unfired bricks

with mud mortar

(Burn) Clay bricks

with mud mortar

Fired bricks

with cement mortar



Dr. Viviana Novelli

A3O

B2M

BE CAREFUL!!



A3O

B2M

0.29 0.11 0.15



A3O

B2M

0.29 0.11 0.15

a) b)a) bad b) good



A3O

B2M

0.29 0.11 0.15

M



A3O

B2M

0.29 0.11 0.15

MM

Construction details

Low maintenance

Low construction details

Good maintenance

Good construction

details

Medium maintenance

Good construction

details



A3O

B2M

0.29 0.11 0.15

MM



Dr. Viviana Novelli

A3O

B2M

0.29 0.11 0.15

MM

N



Dr. Viviana Novelli

A3O

B2M

0.29 0.11 0.15

MM

Y N



A3O

B2M

0.29 0.11 0.15

MM

Y N



A3O

B2M

0.29 0.11 0.15

MM

Y N

B



A3O

B2M

0.29 0.11 0.15

MM

Y N

B

Concrete ring beams



A3O

B2M

0.29 0.11 0.15

MM

Y N

B

Wall plate



A3O

B2M

0.29 0.11 0.15

MM

Y N

B

Buttress



A3O

B2M

0.29 0.11 0.15

MM

Y N

B

No wall plate

No ring beam

No buttresses



A3O

B2M

0.29 0.11 0.15

MM

Y N

B

RELIABILITY?

H




1. URBAN DATA









0.8 8



0.8 8

• Specify whether is settlement of W= wall, P= pillar, F=floor, R=roof; settlement

entity;

• estimate amount of settlement in meters, negative if swelling;

• settlement position: C= centre of façade, EL=left edge of façade, ER= right edge,

EB= both edges, refer to drawing below for position and revers form if swelling



0.8 8



0.8 8

PORTICO: a structure consisting of a roof supported by columns at regular intervals,

typically attached as a porch to a building.

length

depth

# pillars/columns = 3



Single columns

Roof is simply

sit on the

columns

This is not a

portico!!



Portico: yes

0.8 8

Re-entrant corner: yes

1.2 3.0 3+ Re-entrant corner: yes



0.8 8

+ Re-entrant corner

Length and Depth:



0.8 8

Chimney



0.8 8



0.8 8

RELIABILITY?

H




1. URBAN DATA









Damage is collected at the local level on piers and spandrels



PIER: vertical element. Ex: panel between openingsPIER: vertical element. Ex: panel between openings, or

between the edge of a façade and an opening



PIER: vertical element. Ex: panel between openings, or

between the edge of a façade and an opening, or the entire

façade, if this is with no opening



SPANDREL: Horizontal element. Panel on the top or bottom of an

opening.



Number piers and

spandrels

Record the damage

type



Dr. Viviana Novelli

0) No damage

1) Light Damage

2) Structural Damage

3) Near Collapse

4) Collapse

Record the damage level



Number piers and

spandrels

Record the damage

type

The damaged pier is the second vertical element at the first

level. Type of damage D1, level of damage: Significant

Damage (SD)



Number piers and

spandrels

D1 SD

The damaged pier is the second vertical element at the first

level. Type of damage D1, level of damage: Significant

Damage (SD)



1 2 3 4



1 2 3 4

V-D1 SD V NC



1 2 3

V-D1 SD V NCD2 LD D2 LD



12

34

12

3

D2 LD V LD V LDV LD V LD

Top of the

openings

Bottom of

the

openings



We will look at the 7th section during day 5

malawian buildings. - bristol

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