cw a3 1 1 special spec earthwork

8/11/2019 CW A3 1 1 Special Spec Earthwork

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Great Socialist People's Libyan Arab JamahiriyaRailway Section Sirth - Benghazi

Civil Works

Section A3-1-1

Great Socialist People's Libyan Arab JamahiriyaGeneral Authority for Transport and Communications

Railway Executive Board

Section A 3-1-1: Special Specification for

Earthworks, Drainage, Fences, Roads

April 2007


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Great Socialist Peoples Libyan Arab JamahiriyaRailway Section Sirth - BenghaziCivil Works

1 Introduction 1

1.1 Contract Drawings - Working Drawings 1

1.2 Right-of-Way Limits 2

1.3 Laboratory Equipment 2

1.4 Weather and Rail Temperature Recording Station 2

1.5 Bill of Quantities 2

2 Demolition Work and Alterations 3

2.1 General 3

2.2 Demolition and Earthworks 3

2.3 Clearing and Grubbing up 3

2.3.1 Scope 3

2.3.2 Clearing 3

2.3.3

Grubbing-up 4

2.3.4 Disposal 4

2.3.5 High and Low Tension (< 11 kV), Telephone Lines etc. 5

3 Preliminary Remarks and Preparatory Earthworks 5

3.1

General 5

3.2 Soil Surface and Underbrush 5

3.3 Top Soil 6


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3.5.4

Properties of Sabkha 8

3.5.5 Construction 8

3.5.6 Grains size distribution plots for the materials in Sabkhas 10

3.5.7 Construction Sketches in Sabkha locations 11

3.5.8

Soil exchange or treatment 14

3.5.9 Geogrids and Geotextiles 15

3.5.10 Settlement Control 16

3.6 Protection against Sand Drifts 16

3.6.1

Areas with sand drift risks list of protection measures 17

3.6.2 Measures to avoid and minimize significant impacts 19

3.7 Noise protection 21

3.7.1 Noise Protection Measures 21

3.7.2 Requirements for Noisebarriers: 21

3.7.3 Type of Noisebarrier 22

4 Cuts 23

4.1 Construction of Cuts 23

4.2 Establishing the Substructure 26

4.3 Tolerances in Surface Levels 28

5 Structural Excavation 28

5.1 Description 28


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5.8

Water in Excavation 30

5.9 Refilling of Foundation Pits 30

5.10 Permeable Backing to Earth Retaining Structures 30

6 Embankment Fills 30

6.1

Cross Sections 30

6.2 Subballast 32

6.2.1 KG 1 (Rail Norm BN 918 062) 32

6.2.2 KG 2 (Rail Norm BN 918 062) 32

6.3

Subgrade 1 33

6.4 Subgrade 2 33

6.5 Foundation Improvement Layer 33

6.6 Drainage layer 34

6.7

Testing Methods 34

6.8 Slope 35

6.9 Embankment and Culverts 35

6.10 Construction of Borrow Pits 36

6.11

Material 37

6.12 Performing the Excavation 37

6.12.1 Excavation to Formation Level 38


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6.18

Subgrade Soil Compaction 42

6.19 Embankments at Approaches to Bridges 43

6.20 Reinstatement of Damage by Rain 43

6.21 Slips, Subsidence and Overbreaks 43

6.22

Backfill of Road bridges 44

6.23 Backfill of Culverts 44

6.24 Additional Earthwork Requirements for Roads 45

6.24.1 General 45

6.24.2

Compaction of Earthworks for Roads 45

6.24.3 Sampling and Testing 47

6.25 Tolerances in Surface Levels 48

7 Overhaul and Embankment in Place 48

7.1

Overhaul measurement 48

7.2 Embankment in Place 49

7.2.1 Method of measurement for embankments 49

8 Roads and Traffic Areas 50

8.1

Classification 50

8.1.1 Highways 50

8.1.2 Branch Roads 50

8 1 3 A i lt l R d 50


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8.2.3

Vertical Design Elements 54

8.2.4 Geometry of the Cross Sections 56

8.2.5 Intersections 58

8.3 Road Layer Structures 61

8.3.1

Highways 61

8.3.2 Agricultural Roads and Branch Roads 62

8.3.3 Gravel Roads 64

8.3.4 Traffic Areas in Stations 65

8.3.5

Pedestrian Areas 65

8.4 Base Courses 66

8.4.1 Scope 66

8.4.2 Contractors Personnel 66

8.4.3 Materials 66

8.4.4 Equipment 68

8.4.5 Construction Methods 68

8.4.6 Thickness and Finish 69


8.4.8 Maintenance 69

8.4.9 Measurement 69

8.4.10 Payment 70


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8.5.6

Thickness, Finish and Surface Regularity 83



8.5.9 Payment 87

8.6

Concrete Slabs 88

8.6.1 Scope 88


8.6.3 Materials and Structure 88

8.6.4 Equipment 89

8.6.5 Submissions 89

8.6.6 Construction 90

8.6.7 Thickness and Finish 93



8.6.10 Payment 97

8.7 Marking the Road Surface with Reflecting Paint 98

8.7.1 Scope 98


8.7.3 Material 98

8.7.4 Equipment 98


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8.8.4

Flagstones (Concrete Paving Slabs) 102


8.8.6 Payment 103

8.9 Concrete Elements cast in place 103

8.9.1

Scope 103

8.9.2 Design 103

8.9.3 Class of Concrete 103

8.9.4 Lines and Grades 103

8.9.5 Transverse Expansion Joints 103

8.9.6 Dowels at Expansion Joints in Channels 104

8.9.7 Contraction Joints 104

8.9.8 Steel Tie Bars 104

8.9.9 Curing of Concrete 104

8.9.10 Backfilling 105


8.9.12 Payment 105

8.10 Level Crossings in Stations 105

8.10.1 General 105

8.10.2 Payment 106

8.11 Platform Edge Stones 106


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8.12.2

Execution 108

8.12.3 Payment 108

8.13 Crash Barriers (Guard Rails) 108

8.13.1 General 108

8.13.2

Contractors Personnel 110

8.13.3 Material 110

8.13.4 Construction of Crash Barriers (Guard Rails) 112

8.13.5 Measurement and Payment 113

8.14

Concrete Guard Blocks 113

8.14.1 General 113

8.14.2 Material 114

8.14.3 Setting 114

8.14.4 Measurement and Payment 114

9 Drainage of Surface Water 114

9.1 Draining of Track Areas 114

9.1.1 Drainage Trenches 114

9.1.2 Collecting Shafts 115

9.1.3 Discharges 115

9.1.4 Gutter 116

9.1.5 Underdraining of Embankment 116


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11.4

Woven Wire 130

11.5 Staples, Fence stays and Tie Wires 131

11.6 Concrete Footings 131

11.7 Gates and Gate Fastenings 131

11.8

Details of Construction 131

11.9 Measurement and Payment 132

12 Water 132

12.1 Existing Water Courses 132

12.2

Water Procurement 133

13 Surveying 133

13.1 General 133

13.1.1 Drawings 133

13.1.2

Markings 133

13.1.3 Accuracy Requirements 134

13.1.4 Acceptance 134

13.1.5 Markings 134

13.1.6

Construction Supervision 134

13.1.7 Costs of Surveying and Stake-Out Work 134

13.2 Location Survey 135

13 3 Measurement of Heights 135


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13.7.2

Identification of Marking Points 138

13.7.3 Track Acceptance 138

13.7.4 As-Built Plans and Drawings to be Set Up by the Contractor 138

14 Grade and Alignment Control 138

15

Maintenance 139


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Abbreviations

AASHTO American Association of State Highway andTransportation Officials

ASTM American Association of Testing of Materials

BoQ Bill of Quantities

BPM Bid Project Manager

BSC Base Station Controller

BS British Standard

BTS Base Transceiver Station

CBR California Bearing Ratio

CTC Centralised Traffic Control

CUG Closed User Group

DB AG German Railways

DC Direct Current

DIN Deutsches Institut fr Normung;German Standards Institute

EDSS1 European Digital Subscriber Signalling

System no. 1

EI Electronic Interlocking

EIR Equipment Identity Register


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FHO Final Handing Over Certificate

FIS Functional Interface Specification

fob free on board

FRS Functional Requirements Specification

GCR Group Call Register

GE Gravel eng gestuft= Gravel close particlesize distribution acc to DIN 18196

GI Gravel intermetierend gestuft=Gravelmedium particle size distribution acc to DIN18196

GU gravel with clay content acc to DIN 18196

GW Gravel weit gestuft=Sand wide particle sizedistribution acc to DIN 18196

GMT Greenwich Mean Time

GMMRA Great Man Made River Authority

GPS Global Positioning System

GSM Global System for Mobile communication

GSM-R GSM for Railway Application

HT High Tension

ISDN Integrated Services Digital Network

ISO International Standardisation Organisation

ITU International Telecommunication Union


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PE Polyethylene

PIS Passenger Information System

PM Project Manager

PS Power Supply

PVC Polyvinyl chloride

RAS Railway Application Subsystem

REB Railway Executive Board

SE Sand eng gestuft=Sand close particle sizedistribution acc to DIN 18196

SI Sand intermetierend gestuft=Sand mediumparticle size distribution acc to DIN 18196

SU Sand with clay content acc to DIN 18196

SW Sand weit gestuft=Sand wide particle sizedistribution acc to DIN 18196

TS Technical Specification

UIC Union Internationale des Chemins de Fer

UP0 ISDN Interface Standard

VDE Verband der Elektrotechnik, Elektronik undInformatoinstechnologie; Association for

Electrical, Electronic and InformationTechnologies

VGCS Voice Group Call Service GSM servicedeveloped for railways, later generalised aspart of the so called GSM ASCI features


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1 INTRODUCTION

The project to which these Special Specifications refer is the Sirth - Benghazi railway linefor its total overall length and including the Passenger Freight stations and Shunting yardsas detailed in the plans and other contract documents.

Where disagreement between the content of the General Specifications and the content

of these Special Specifications exists, the content of these Special Specifications arethe only one valid.

The works covered by these Special Specifications are the works related to theconstruction of the open line sections, the station complexes, roads, paved areas, etc.The works required are characterized by the following main construction categories:

Demolition Work and Alterations

Preparatory Earthworks

Cuts

Embankment Fills

Approach Blocks for Engineering Structures

Roads and Traffic Areas

Drainage

Ballast

Slope protection

1.1 Contract Drawings - Working Drawings

The contract drawings as per list attached are intended to be indicative of the standardtype of work, structures and interventions required from the Contractor.

These standard types of work, structures and interventions shall anyhow be subject of


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1.2 Right-of-Way Limits

The right-of-way limits to be respected by the Contractor shall be, at least, the following:

on open line: 50 m on each side of the future double track center line

in stations: as shown in the layout of the stations

1.3 Laboratory Equipment

For impeccably carrying out the Earthworks, the availability of a well-equipped soilmechanic laboratory is indispensable.

The items to be supplied are listed in the General Specifications.

1.4 Weather and Rail Temperature Recording Station

The Contractor shall furnish a small weather station and daily collect the necessaryinformation.

In addition, the Contractor shall furnish a recording thermometer to be used for thecollection of the temperature of the rail during the 24 hours of the day.

This thermometer shall be capable to record on special paper the temperature variationsduring the day and the sane strip shall last preferably for one day and/or for the maximumperiod of one week.

The accuracy of the recording shall be one degree centigrade minimum.

The rail from which the temperature is collected shall be equal to that adopted for theproject, at least 1.50 meter long, and shall be continuously exposed to the sun-rays,during the light-hours.

The collection of data and the thermometer paper-strips shall be delivered daily or weeklyofficially to the Engineer.

The Contractor shall supply the thermometer not later than 60 days from the signature ofcontract and the collection of data shall be continued up to the end of the maintenanceperiod.


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2 DEMOLITION WORK AND ALTERATIONS

2.1 General

As a matter of principle the tenderer has to familiarize himself, prior to submitting hisoffer, with the scope and number of objects and buildings to be demolished along the line.This holds especially true for the building material of the parts to be demolished, becauselater they cannot be cited for additional payment, even if the description in the Tender

Documents proved to be inaccurate. Only approximate values are stated in the Bill ofQuantities as regards the quantity of objects to be demolished.

While the demolition- and alteration work is under way, the existing cable ducts, as wellas sewer pipes and rainwater pipes are to be protected such that they remain fullyoperational until the new ducts and pipes are installed.

In case any cables or other ducts will be damaged by the Contractor due to his executionof the work, the Contractor is responsible for the immediate repair, and the Employerdoes not have to request this to be done. The cost for such repairs is to be borne by theContractor himself. Any other costs or expenditure resulting from the Contractors notsufficiently knowing the construction site, will not be refunded.

2.2 Demolition and Earthworks

Before the demolition works start the location of pipes and cable at the construction sitehas to be clarified. These pipes and cables have to be protected during demolishing

works and other construction works as instructed by the Engineer.

Cables and pipes to buildings, which have will be demolished, have to be taken out ofoperation before start of demolition works.

2.3 Clearing and Grubbing up

2.3.1 Scope

The Contractor shall demolish, break up and remove all buildings, structures andsuperficial obstructions on the site in the way of or otherwise affected by the works. Heshall clear each part of the site at times and to the extent required or approved by theEngineers representative.


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performance of this work. Trees or shrubs outside roadway excavations or elsewhere tobe left in place shall be protected from injury during construction operations.

Bushes, undergrowth, small trees the trunks of which are less than 30cm in girth at 90cmabove ground level, tree stumps less than 10cm diameter and hedges shall be uprootedand burnt or otherwise disposed of.

2.3.3 Grubbing-up

All topsoil under any construction shall be completely removed and stored in anappropriate way to be used at a later stage unless otherwise directed by the Engineersrepresentative. All topsoil in borrow pit areas shall be treated in the same way.

In roadway excavation areas all stumps and roots shall be completely removed and allstructures, walls, or other objectionable matter other than soil shall be removed within adepth of at least 60cm below formation level and side slopes and within a depth of at least

30cm below bank slopes. Any parts of structures below these levels shall be cleared out,walls and floors punctured in order to prevent retention of water and the whole filledsolidly with approved material and compacted to the satisfaction of the Engineer srepresentative. All stump and root holes shall be backfilled with approved material andcompacted to the same density as the surrounding material.

Borrow areas and excavation areas from which fill material will be taken shall be grubbed-up to remove all heavy grass, weeds or other vegetable growth, and all stumps, roots orother objectionable matter removed completely to exclude such matter from the materialsto be used in construction.

Embankment areas shall be grubbed free from heavy grass, weeds or other vegetablematter to sufficient depth to enable a minimum depth of 90cm of filling from formationlevel, or to suit such depth of filling as otherwise directed by the Engineers representativeto suit the material and site conditions.

All stumps and roots shall be completely removed. All stump and root holes shall be

backfilled with approved and compacted material so that its load bearing capacity equalsthat of the surounding material.

All stumps within the right-of-way, but outside the excavation or embankment area, shallbe removed to a depth of at least 30cm below the original ground surface and the stumpholes backfilled with approved material so that the ground surface will be uniform.


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2.3.5 High and Low Tension (< 11 kV), Telephone Lines etc.

Overhead electric and telephone lines and the like crossing or interfering with the workshave to be dismantled acc. to the regulations and the requirements of the concernedauthorities after approval of the Engineer. All a.m. lines have to be reinstalled as it isusual practice and as approved by the authorities and the Engineer.

3 PRELIMINARY REMARKS AND PREPARATORY EARTHWORKS

3.1 General

Part of the earthworks are embankment fills, cuts, catch ditches, as well as winning fillmaterial on the sides, the transport of the same, installation, and compaction. Wayleaveand the limits for winning material normally reaches up to 50 m on both sides from thecentre axis of the future embankment.

The quantity survey will be carried out always only after the work has been entirelycompleted, and it will be done together with the Engineer. Only such installed quantitieswill be paid that are without fault and do correspond to the drawings, materials prescribedand the technical descriptions.

The following tolerances are to be adhered to for the railway formation:

Accuracy of position of the embankment: 5 cm

Accuracy of level of the finish grading 2 cm

Accuracy of level of the ballast 40%of which is to be installed by the Contractor for Earthworks 2 cm

The expenditure for the control measuring cannot be claimed by the Contractor for extrapayment. If so requested by the Engineer, the Contractor has to provide the auxiliarypersonnel required for the surveying and soil testing work effected by the Employer.These personnel will be on the Contractors payroll and payment will be made by him.

On the basis of soil samples having been taken at the places where later the soil is to bewon and on the basis of the tests carried out with these samples it can be taken as giventhat a certain percentage of water will be needed for the compaction of the soil.


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3.3 Top Soil

The top soil is to be expected along the line only in cultured and irrigation areas. In casesuch top soil is found, it is to be shoved entirely off and stored on the sides.

The top soil is to be stored in such a manner that it is protected from erosion through windand water and is re-usable after the construction.

In each case the Engineer will decide, where the top soil is to be shoved off, in whichquantities, and where it is to be stored.

3.4 Interchange and Soil Stabilization

3.4.1 General

In the areas where the natural ground is composed of highly compressible soil, salt or the

same is characterized by the presence of a high water table, the Engineer shall order theimprovement of the foundation which shall foresee the removal of the existing materialand its substitution with selected fill. Such areas, where the load-bearing capacities of thefoundation are insufficient, are mainly encountered in the Sabkha area.

In some locations the soils of inadequate load bearing capacity mainly consist of recentdunes; under a sometimes thin surfacing layer of medium-stiff consistency very soft oreven pasty silts were encountered. It is required to exactly determine the length,thickness as well as depth of the dunes by performing additional penetration tests by theContractor. The same applies to establishing the extent of the unsuitable soil in theSabkha areas.

In the sand dune areas explorations shall be performed down to the load-bearing layersat 50 m intervals and/or as directed by the Engineer, where the sands are reaching belowgrade.

Where the foundation is very soft and pasty the explorations shall reach down to a

minimum depth of 3.0 m and/or until layers of adequate load-bearing capacity areencountered.

In areas where the existence of very soft and pasty soils is known but where as a result ofthe topographic and geological situation subsurface conditions cannot be excludedsounding rods shall be driven into the ground for a minimum of 4m in and at 100 m


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Pleistocene (Quarat Weddah and Al Hishash Formation) deposits. The coastal sabkhasare still in a depositional phase. Their maximum thickness is estimated to reach 10 m, avalue that was confirmed by the results of the geotechnical exploration. The generalcontent of the coastal sabkhas is dominated by redish silts with layers gypsum and halite.They are almost always covered by a layer of soft, black (organic content), strongsmelling mud. The mud layer reaches a thickness of about 0,1 m to 0,3 m. The result ofour geotechnical investigation suggests that in some areas especially closer to the coast,a more predominant sand fraction is apparent in the sabkha strata.

Most of the sabkhas are flooded at long intervals. Some are also connected to thermalspring activity. Since most of the sabkhas lie below sea level an influx of seawater can notbe ruled out but would be fairly restricted, otherwise their surface level could not be drybelow sea level.

3.5.2 Location of Sabkhas

Sabkhas occur all along the Libyan coastline, whenever the geomorphologic conditionsare favorable. The first sabkhas in the vicinity of the railway corridor occur about 60 kmeast of Sirth with the Sabkhas al Hushayfat, abu Gasaba, al Naim and al Zehayar. Theyhave a cumulative extend of about 25 km in length and a maximum width of 4 km.

The next extensive sabkha area occurs between Bin Jawad and Ras Lanuf. Their extendis limited to the very vicinity of the coast and they do not affect the construction of therailway line.

The next notable Sabkha, and the only large one that actually intersects the railwaycorridor is the Sabkha al Kabirah. The crossing lies about 44 km south east of Ras Lanufand is approximately 500 m wide. Since the sabkha al Kabira extends far inland, anddoes not extend parallel to the coast it can probably be classified as an inland sabkha.The next sabkha occurs 20 km east of Al Aqaylah and is the sabkha al Muzayyarah. Thisone again is a classic example for a coastal sabkha. The area around Marsa al Brega isdotted with of numerous coastal an inland sabkhas. Here the alignment runs inland thesmaller inland sabkhas but crosses a small portion of a the larger Sabkha al Hafirah. The

sabkhas near Marsa al Brega continue along the alignment right through to Ajdabiya.They are intersected and overlaid by sand dunes, thus not always easily identified. Thealignment was chosen to avoid most of the sabkhas which can propose problems duringthe construction process. After Ajdabiya the alignment passes the coastal sabkhas farinland so no more crossing occur between there and Benghazi.


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3.5.4 Properties of Sabkha

min max mean

cohesion [kn/m2] 0 3,56 0,8

angle of friction

[degrees]

29,95 37,24 33,3

bedding coefficient

ks[kn/m3] 1)

9200 23600 15000

permeability [m/s] 4,5 x

10-52,81 x

10-49,0 x

10-5

TABLE: PROPERTIES OF SABKHA

1)measured in the upper 2 m

The grain size distribution charts are attached directly to this chapter.

3.5.5 Construction

Embankment construction in the sabkha areas is difficult due to the following mainreasons:

Large and long lasting settlement due to the low natural compaction of the ground, itsorganic content and the fact that all of the sabkha sediments can be beneathgroundwater level. Especially in fine grained sediments the pore water pressure isreleased very slowly, leading to long lasting settlement and renewed settlement underdynamic loads.

Failure of the embankment under its own load or the dynamic loads induced by rail


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To minimize the risk of ground failure the minimum foundation depth under the sabkhasurface is 3.00 m. This also prevents excessive settlement from the upper, leastcompacted layers.

The actual foundation depth depends on the height of the embankment.

The following construction work has to be executed:

Construction of longitudinal drains at a level of 2.0 m below foundation level.

Draining until the water level is below the foundation level and continuing dewateringduring construction phase.

Removal of sabkha material to the foundation level, with an appropriate slope angle.The slope stability has to be calculated and handed in for inspection by the contractor.

Laying of geotextiles and geogrids.

Construction of the foundation layer.

Construction of embankment.

Laying of track work can only commence after all settlement has occurred. Thecontractor shall prove that fact and shall seek final approval by the engineer beforecommencing with the laying of ballast and rails.

The contractor has to prove the stability of the embankment, and shall propose necessarychanges such as a deeper foundation layer if the embankment safety cannot be provenwith the given design.

For roads and other traffic areas the embankments in the Sabkha areas shall beconstructed in an analogue way as the railway embankment. The contractor shall submitdetailed shop drawings that have to be approved by the engineer before starting with the

embankment works for the roads and traffic areas.


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3.5.6 Grains size distribution plots for the materials in Sabkhas

These 2 plots are typical grain size distribution for the materials in the Sabkha locations.

0

10

20

30

40

50

60

70

80

90

100

0.01 0.1 1 10 100

diameter, mm

%Passing

CHART: GRAIN SIZE DISTRIBUTION 1

20

40

60

80

100

120

%Pas

sing


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3.5.7 Construction Sketches in Sabkha locations

3.5.7.1 Height of Embankment < 2.00 m


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3.5.7.3 Details


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3.5.8 Soil exchange or treatment

The soils with insufficient load bearing capacity shall be excavated completely as directedby the Engineer. The maximum proposed depth of the excavation shall be 3.0 m. Thebottom width of these excavations shall ensure that the slope of the dam of 1:2 willcontinue in the ground down to the bottom of the excavation. Dewatering by the drainagemethod shall be provided where as directed by the Engineer.

Cohesive soils with a sufficient load bearing capacity shall have at least a stiff

consistency. Non cohesive soils should be at least medium densely packed.

The removed material shall be transported to an area outside the right-of-way to dumpingareas approved by the Engineer.

The selected fill material, shall have the required properties as stated in chapter 6.5 and6.6.

The contractor is required to bring to the attention of the Engineer any other possible wayof improving the foundation layer that will be more economical than a soil exchange.Failure to do so will result in deduction of payment.

After the filter material has reached the natural ground level, the elevation or thethickness ordered by the Engineer, the Contractor shall begin the construction of thenormal embankment.

A drainage layer shall be constructed in the places ordered in writing by the Engineer,who shall also fix, for each stretch, the dimensions of the work and the thickness of thelayer.

Any of the following positions and stretches anyhow shall be checked by the Engineerduring the work and variated or cancelled, if so found, on the basis of the results of thenew tests carried out.

Measurements of the drainage layer shall be made per cubic meter and the payable

quantity shall be obtained from the consideration of the area on which the improvementhas been ordered by the thickness, fixed by the Engineer.

In case the Contractor shall have excavated and consequently refilled more, then thethickness fixed by the Engineer shall be considered valid for accounting purposes.


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Layers of 0,3 m thickness Ev2of 20 MN/m

2shall be reached.

In case the Engineer may consider it necessary, plate bearing tests shall be carried out.

A soil exchange shall be constructed in the place where it is necessary to do so. Priorapproval has to be obtained in writing by the Engineer which states the length, thedimensions and the exact beginning and end point of each improvement section.

3.5.9 Geogrids and Geotextiles

3.5.9.1 General

As far as the mechanical and hydraulic filtration stability can not be assured in the planebetween the subsoil and the reinforcement layer a geotextile separation and filtration layerfor example Secutex R 201 GRK 3 see datasheet or another material with equivalentproperties has to be placed between the subsoil and the geogrid to prevent pumping offines into the base course layer. This becomes essential to ensure the internal angle offriction.

3.5.9.2 Embankment Construction

On the base of the foundation level a geotextile (geogrid Type Secugrid 40/40 Q 1 oranother material with equivalent properties as shown in the below table for geogrids) has

to be placed. On top of this geotextile a separation layer as described above has to beplaced (see drawing details before). The next layer shall be the granular gravel layer in1.20 m thickness. On top of the gravel layer a second geogrid has to be placed. Thegeogrid must be placed with a overlapping as structural required and required due to themanufacturers guideline.

Material Properties of Geotextile


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3.5.9.3 Material Properties of Geogrid

TABLE: MATERIAL PROPERTIES OF GEOGRID

3.5.10 Settlement Control

Every 200m in longitudinal direction settlement gauges have to be installed in the

embankment at Sabkha locations and the settlement has to be monitored during theconstruction times in intervals as instructed by the Engineer. The Contractor shall recordthe data.

The data shall be compared with the settlement predictions and the settlement predictionsshall be updated accordingly. The construction of the trackwork shall only commenceafter the main amount of settlement has occurred. Residual settlement after constructionshall not affect the track geometry. The settlement predictions and the measurement

results have to be supplied to the engineer and the engineer has to agree to thecommencement of the track construction.

3.6 Protection against Sand Drifts

Locations of potential Sand drifts:


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3.6.1 Areas with sand drift risks list of protection measures

Corridor

Selection

S-B km Area Kind of risk

Part 1 1065,4 1066,4 Harawa Town,East of HarawaPassenger Stationca. 1000 m of route

Sand drifts of DuneStructures,Covering of rails

Measure MS 12

Part 1 1094,9 1102,0 Umm Al KhanfisTown,

ca. 6.600 m of route

Sand drifts of DuneStructures,

Sand DuneMovements,Covering of rails

Measure MS 11

Part 3 1277,0 1291,0 Al Agaylah,ca. 14.700 m of route

Grinding effects ofSand grains,

Sand drifts,Covering of rails

Measure MS 10

Part 3 1305,0 1309,4 East of Al Bishr,ca. 4.600 m of route

Grinding effects ofSand grains,Sand drifts

Measure MS 9

Part 3 1309,8 1310,7 East of Al Bishr,ca. 800 m of route


G t S i li t P l Lib A b J hi i


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CorridorSelection

S-B km Area Kind of risk

Part 3 1335,5 1338,8 East of Al Braygha,ca. 3.500 m of route

Grinding effects ofSand grains,Sand drifts,

Covering of rails

Measure MS 6

Part 4 1361,4 1363,7 East of Al Braygha,ca. 700 m of route


Measure MS 5



Measure MS 4

Part 4 1369,6 1371,0 East of Al Braygha,ca. 1.000 m of route Grinding effects ofSand grains,Sand drifts

Measure MS 3



Sand driftsMeasure MS 2

Part 5 1425,7 1426,7 West of SultanAjdabiya,


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3.6.2 Measures to avoid and minimize significant impacts

In General two different kinds of sand drifts exist:

Primary sand drifts: the sand itself comes directly from a dune, stopping the first timeat the object to be protected

Secondary sand drifts hills: the sand is coming from sand deposits near the railwayline. The sand was stopped, collected by rails, steep embankments.

Sand drifts in general and particularly in the field railways, can only occur when thefollowing inconvenient circumstances are combined together:

wind speed of min. 5m/second

great quantities of sand

wind direction is perpendicular to object

reduction of wind speed in the vicinity of the object

According to the experiences of comparative projects in arid areas there will be twogeneral kinds of sand drift risks:

Covering of tracks/rails and buildings by sand drifts and sand dune movements

Damage of rails and buildings by the grinding effect of sand and fine gravel

For the railway line Sirth-Benghazi the following proposals/solutions will be executed:

1. profiling of embankment with coarse material for open desert sections (track onembankment 1 m) in longer sections of sand drift risks



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2. profiling of embankment with coarse material for open desert sections(track on embankment >3 m) in longer sections of sand drift risks

SKETCH: PROPOSAL 2 OF SAND DRIFT PROTECTION

3. Prevention in open desert with sand traps and walls in longer sections of sand driftrisks

SKETCH: PROPOSAL 3 OF SAND DRIFT PROTECTION

4. Prevention in cuttings with sand traps and walls



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5. Planting of trees and brushes, afforestations in regions with sufficient precipitation.

6. Sand protection fences for short sections of sand drift risks

3.7 Noise protection

Before start of work the locations of possible Noise protections has to be checked andverified by the Contractor. A report about the locations has to be submitted to theEngineer. The Engineer will inform the Contractor about the final locations of noise

barriers and what measure at each location will be carried out.

1. Areas with potential noise pollution are estimated on the base of experiences fromcomparative projects under regard of the peculiar topographic situations in theinvestigation region.

3.7.1 Noise Protection Measures

Number ofmeasure

Area

MN 0 Al Maqrun, km 1476 1478MN 1 and MN 2 Scattered houses west of Sultan Ajdabiya, km 1431

- 1434MN 3 Bin Jawad, km 1144 - 1149MN 4 and MN 5 Harawe town, km 1064 1067MN 6 Scattered houses amera housing, km 1058 1060

MN 7 Athar Brnayaf al Hadid, Ummayyid Qabush, km1037 1039

TABLE: LIST OF NOISE PROTECTION MEASURES

3.7.2 Requirements for Noisebarriers:

The requirements for the noise barriers are:

Noise protection measures are only in residential areas and settlements necessary

The design speed will be 250 km/h



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A handrail must be provided at the side towards the railway

The noise barrier must be able to reduce the noise to a level of 60 dB(A) at daytimeand 70 dB (A) at night time.

Doors have to be installed in the noisebarriers at every 200 m

3.7.3 Type of Noisebarrier

The type of noise barrier shall be as follows:



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4 CUTS4.1 Construction of Cuts

Cuts in the territory in rock or soil are to be protected at the slopes against largequantities of surface water or artesian water in order to prevent slope failure and erosion.

This should be achieved with a drainage ditch at the upper edge of the slope which willdivert the surface water in a suitable direction. The dimensions of the ditches should besufficient to carry all surface water. The decision as to whether ditches are necessary willbe taken by the Engineer.

In rock cuttings it should be observed that there are no discontinuities in the rock that cancause slope failure at a later stage. All the final surfaces have to be approved by theengineer. In case of loose and unstable blocks, protections measures have to be taken.All protection measures have to be approved by the engineer.

For cuttings in soil, the contractor shall carry out the cuttings with an economical and safeangle of slope. The contractor has to prove the long term safety of the cutting and presentthe proofs to the engineer. In case of possible erosion through wind or water, slopeprotections shall be applied to the slopes.

At the foot of each slope there shall be sufficient room for an intercepting ditch thatprevents falling rock and soil from falling directly on the tracks. Alternatively protectionmeasures like nets can implemented with approval from the engineer.

During the construction of the rock cuttings the contractor shall take care not to disturbthe insitu rock more than necessary. Blasting should be kept to a minimum.

Cuts that reach into the ground water table shall have adequate draining facilities that willkeep the groundwater level at a depth where it does not influence the earthwork structure.

Rock shall include only hard material or rock found in ledges or masses in its originalposition which in the opinion of the Engineers Representative is impossible to remove byheavy mechanical excavating plant or by heavy duty hydraulic ripper, or by approvedpneumatic tools, and which would normally be removed by blasting with explosives, or bydrilling and broaching with wedges and sledge hammers if removed by hand. Alsoindividual boulders or detached pieces or rock exceeding one quarter cubic metre in sizein trencher; one metre in width or less and exceeding one half cubic metre in general



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contain strata classified as Rock Excavation and the various strata or membersthemselves are parted with strips or strata classified as Common Excavation and thestrips or strata constitute less than fifty (50) percent of the total thickness of the memberportion of member a combination of members, the entire volume of member portion ofmember or combination of members below the stripped overburden shall be paid for asRock Excavation Where the percentage of strata classified as Common Excavationisgreater than fifty (50) percent of the member below the stripped overbunden, the entirevolume of member, portion of member or combination of members below the strippedoverburden shall be paid for as common excavation.

The Contractor shall at all times observe and comply with all State laws, Regulations andRules which in any manner pertain to the handling, transportation and storage ofexplosives and the safety of persons and property.

The Contractor shall only store explosives in a licensed or approved store or magazineprovided with a separate compartment for detonators. The Contractor shall provide properbuildings for the store or magazine in locations to be approved by the Engineer as

suitable for the storage of explosives in manner and quantities to be approved; he shallalso be responsible for the prevention of any unauthorised issue or improper use of anyexplosives brought on the Works. Only responsible and experienced men shall beemployed for handling explosives which shall be used in the quantities and mannerrecommended by the manufacturers and in conformity with the statutory regulations.

The Contractor shall provide at the explosive store the necessary watchman day andnight and shall make his own arrangements for safe transport of explosives.

The water ditch to be provided at the foot of the slope should have the following minimumdimensions under normal circumstances:

depth: 0.50 m

width of the bottom: 0.50 m

The dimensions have to be adjusted to the hydrological requirements.

When rocks are stripped special care must be taken that the fissure surfaces will not beleft in such a way that the rock plates can later slide down.

The Engineer will decide in each case on the slope grades. Under normal circumstances,however the standard cross sections with the pertaining angles of slope have to be



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The remaining rock material below the sub ballast layer should, if possible, not beloosened. If, however, it has been loosened in cuts, such material is to be removed bysuitable means.

The material thus blasted off is to be crushed to such sizes that it can be used for theadjoining embankment fill.

In all deep cuts (more than 5 m in depth ) core drillings shall be performed by thecontractor before starting excavation in order to determine the final slope inclination with

regard to the prevailing rock layers (mostly gypsum, sometimes, limestone) mixed withlayers of silt, clay and marl rather seldom gravel and sand.

Where anhydrit is encountered 0.30m to 1.20 m below the formation level, this materialshall be excavated and removed for a minimum thickness for 0.50 m and the respectivelayer shall be sealed with cohesive soil (soil group CL, ML acc. to ASTM).



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4.2 Establishing the Substructure

In case a cut is to be provided in rocky ground or in conglomerate, as regards the heightof the embankment crest it should be borne in mind that between top of rock and loweredge of the ballast bed a sub ballast protection layer of 30 cm thickness is to beestablished.

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The material to be used is gravelly sand with a compaction according to 100% of the

modified Procter density. In order to limit the settlements, the Ev2value of the load-platebearing test is to be at least 120 MN/m2.

In case of cohesive or non-cohesive soils it has to be checked, after the cuts have beenestablished, whether there still exist at least an EV2value of 20MN/m

2.

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Foundation improvement layer

A foundation improvement layer has to be constructed if the foundation soil has an Ev2value of less than 20 MN/m2and is not improved through other methods.

The foundation layer shall be constructed from material with the following characteristics:

GU, GT, SU, ST, UL, UM and TL (classification according to DIN 18196) with acompaction ration of Dpr = 0,97.

In case the ground is too bad, the soil is to be exchanged against a better and moresuitable quality. The decision is to be taken by the Engineer.

4.3 Tolerances in Surface Levels

The finished earthworks surface unevenness when tested by a 3m straight edge, bytaking the measurement at the deepest point between two contact points of the straight

edge, shall comply with the a.m. surface level tolerances.The side slopes of rock cuttings need only be trimmed to give an average side slope asspecified; the finished appearance of the rock face will vary to suit the character of therock.

The Contractor shall inform the Engineers Representative in a reasonable time inadvance, of the time and place of work, so as to ensure that the taking of measurements,is of the minimum inconvenience to the Engineers Representative and minimum delay for

the Contractor

5 STRUCTURAL EXCAVATION

5.1 Description

Structural excavation shall comprise and include all pay excavation lying outside the

railway or the road bed excavation cross section required in connection with theconstruction of bridges, box and arch culverts, abutments, piers, retaining walls andbuildings. The work shall be performed in strict accordance with the applicable drawings.

5.2 Inspection

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The Engineer may require the Contractor to excavate below the foundation levels shown

on the Drawings or he may order him to stop when suitable foundation material isencountered.

5.4 Bottom of the Excavation

The bottom of all excavations shall be carefully graded and if required by the EngineersRepresentative stepped or benched horizontally. All excavations shall be taken out asnearly as possible to the exact dimensions of the foundations to minimise backfilling. In

excavations for foundations to structures a bottom layer of soil shall be left in placetemporarily and subsequently removed only when the concrete is about to be placed, inorder that softening or deterioration of the surface of the excavations by exposure may beavoided so far as possible. The thickness of the layer will depend on the type of soil andwill be determined by the Engineers Representative. Any pockets of soft material or looserock in the bottoms of pits and trenches shall be removed as directed and the cavities soformed filled with concrete. After the completion of placing of any blinding concreterequired by the Contract, no trimming of the side faces shall be carried out for 24 hours.

When any excavation has been taken out and trimmed to the levels and dimensionsshown on the Drawings or directed by the Engineers Representative, the EngineersRepresentative shall be informed accordingly so that he may inspect the completed pit ortrench and no excavation shall be filled in or covered with concrete until it has been soinspected and the Contractor has been authorised to proceed with the work.

5.5 Surplus Material

All surplus excavated materials from excavations not required for refilling shall, ifconsidered suitable by the Engineers Representative, be deposited in embankments orotherwise disposed of as directed.

5.6 Excavation Greater than Necessary

Excavation in rock to a depth greater than directed shall be made good by the Contractorat his own expense with concrete.

Excavation in soil to a depth greater than directed shall be made good by the Contractorat his own expense with applicable and approved material.

Excavation to a width greater than necessary in rock shall be made good by theContractor at his own expense by completely filling the excess volume of excavation with

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Quantities, except where in the Engineers opinion the necessity for leaving in the timber

or any other material has arisen from carelessness or neglect on the part of theContractor.

5.8 Water in Excavation

During the time that excavation is being carried out and until the constructional works cansuffer the damage from flooding, all excavations shall be kept free from water.

Where excavations have to be made and foundations formed below the known groundwater level, the Contractor shall submit a full and clear description, supported by suchdrawings as may be necessary of the methods he proposes to use in respect of eachfoundation to enable the whole of the work to be executed in the dry and such measuresshall be adopted as the Engineers Representative approves.

Precaution shall be taken to prevent upward piping of the bottom of excavations either bycutting off sheeting, by lowering the water table or by other means and all such

precautions shall be subject to the approval of the Engineer prior to adoption.5.9 Refilling of Foundation Pits

Refilling of foundation pits and trenches shall be carried out as soon as possible after thefoundations have acquired adequate strength as determined by the EngineersRepresentative.

Refilling may only commence after structural works within the excavations have beeninspected and approved by the Engineers Representative.

Timber sheeting and other excavation supports shall be carefully removed as the fillingproceeds except as otherwise specified or ordered, but the removal of such supports willnot relieve the Contractor of his responsibility for the stability of the works.

5.10 Permeable Backing to Earth Retaining Structures

Where shown on the Drawings or required by the Engineer, back drainage to structuresshall be provided.

6 EMBANKMENT FILLS



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6.2 Subballast

The Subballast can consist either of two mixed materials (named KG 1 and KG 2). Theyhave to adhere to the following specifications:

6.2.1 KG 1 (Rail Norm BN 918 062)

6.2.1.1 General requirements

All materials shall have a high resistance against physical and chemical weathering.

All materials should be highly resistant against mechanical wear especially thoseinduced by dynamic loading.

All materials need to be quality controlled and be approved.

6.2.1.2 Special requirements

The sieve plot of the KG 2 should be a steady curve and it has to fulfil the followingparameters:

o D0,063mm 5,0 Mass % before compaction and 7,0 Mass % after

compaction

o D2,0mm 60,0 Mass %

o D10mm 85,0 Mass %

o Largest grain: 32,0 mm

o Overlarge grain 64,0 mm

o U 15

A permeability-coefficient of k10 < 1 * 10-6 m/s at a Proctor density of DPr= 1,00.

6.2.2 KG 2 (Rail Norm BN 918 062)

6.2.2.1 General requirements



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6.2.2.2 Special requirements

The sieve plot of the KG 1 should be a steady curve and it has to fulfil the followingparameters:

o D0,063mm 5,0 Mass % before compaction and 7,0 Mass % after

compaction

o D10,mm 85,0 Mass %

o Largest grain: 45,0 mm

o Overlarge grain 64,0 mm

o U 15

A permeability-coefficient of k10 5 * 10-5 m/s at a Proctor density of DPr= 1,00.

6.3 Subgrade 1

The Subgrade 1 material should fulfil all the requirements that are stated in the drawings.

Only those materials shall be used for the construction of Subgrade A, that can aftercompaction be classified as GU,GT,SU or ST according DIN 18196.

The compaction ration should be equivalent to Dpr= 1,00.

The strength on the top of the subgrade1 shall not lie below Ev 2= 80 MN/m2

.

All used material has to be pre approved by the engineer and regularly checked for theiraccordance with the requirements. To improve the strength of the subgrade 2 materialcan be treated with soil cement or other applicable and approved methods.

6.4 Subgrade 2

The subgrade 2 material should fulfil all the requirements stated in the drawings. Thesubgrade A can be constructed from the following materials:

GW, GI,GE,SE,SW and SI (classification according to DIN 18196) with a compactionration of Dpr= 0,98.



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The foundation layer shall be constructed from material with the following characteristics:GU, GT, SU, ST, UL, UM and TL (classification according to DIN 18196) with acompaction ration of Dpr= 0,97.

6.6 Drainage layer

In case of a groundwater lever that is higher the embankment footing, a capillaritybreaking drainage layer has to be constructed. The grain size distribution, thickness andcompaction of the layer shall be sufficient to stop all water from entering the embankmentconstruction.

6.7 Testing Methods

The earthworks constructions shall be tested for compliance with the requirements atregular intervals. The testing shall be carried out by the contractor. The contractor shalladvise the engineer where and when he wants to carry out the required tests. The

engineer may at any time order additional tests to be performed.

Type of construction Required amount of tests

Top of sub ballast 6 per 4000 m2

Sub ballast 6 per 4000 m2, every 3rdlayer

Top of sub grade 1 6 per 5000 m2

Sub grade 1 6 per 5000 m2, every 3rdlayer

Sub grade 2 6 per 5000 m2, every 3rdlayer

Top of Foundation improvementlayer

6 per 5000 m2

Foundation improvement layer 3 per 5000 m2, every 3rdlayer

Approach block 6 per 500 m3

Earthworks over culvert 6 in the first meter over the



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Special care has to be taken that the strength in the embankment must be getting more

and more from the lower to the upper layers, as is shown in above drawing. Thecompaction values stated in this drawing must be adhered to by all means.

Only such material is to be used for embankment fills that have previously been checkedas to their compatibility and other properties, and that have been released for use by theEngineer.

For each new material that is used in earthwork construction, the parameter tests have to

be carried out and handed over to the engineer. The main parameter tests include:

Sieve analysis

Proctor density

Natural water content

Dry densityFor this purpose trial fills as specified are to be made for the different types of soil, beforethe embankment work is started.

In case the Engineer finds out that the compaction does not comply with the requiredvalues, a re-compaction is to be done by the Contractor until he can prove that therequired compaction ratio has been reached prior to placing the next fill.

6.8 Slope

In general the slope inclination is to be 1:2.0 or 1:4.0, due consideration given to theprevailing soil conditions.

Due to this relatively flat inclination an erosion of the slopes will be counteracted in asmuch as possible.

During construction the Engineer might direct that the slope inclination is to be reduced toanother slope inclination in sections of high embankment with heights of more than 10m.Furthermore 1:2 slope inclination or even flatter might be directed by the Engineer in thearea, where the footing of the embankment will be situated in water temporarily. Thesame will apply in similar areas of greater Wadis, where banking-up of the water course is

ibl



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Before the actual work is started, it has to be determined how many of the said structures

must be completed before the construction of earthworks can start to implementearthwork measures.

6.10 Construction of Borrow Pits

Borrow pit are used to retrieve suitable construction material for the construction ofearthwork structures. They shall only be constructed in areas where the cuts do not yieldenough suitable material. The construction of borrow pits has to be approved by the

engineer and their suitability has to be proven beforehand by test pits or other suitablemethods. After the excavation of the construction material the borrow pits shall belandscaped and partially refilled.

Depending on the type of soil, being cohesive, non-cohesive, or mixed, the soil mechanicvalues are to be determined prior to the material being filled. By means of these soilmechanic values binding conclusions can be drawn for the place-ability of the material.Furthermore such tests will show which thicknesses are allowed for the fill layers. And this

again determines the stability of the future embankment achieved by the compaction.Such tests are also a means of finding out whether the material encountered can also beused for the sub-ballast layer. All soil mechanic tests and determinations of the screeningcurve will be carried out by the soil-mechanic engineers of the Contractor under thesupervision of the Engineer or the soil-mechanic engineer of the Employer.

If the Engineer believes or is convinced on the basis of the tests carried out that the fillmaterial is not good enough, the borrow of the material at this spot has to be stoppedimmediately. From each borrow point soil samples are to be taken prior to borrowingmaterial, and on these soil samples the necessary tests will be carried out. After the testsshow that the material is fully suitable for an embankment fill, the Engineer will releasethe material.

Borrow material for fill shall be obtained from the borrow areas designated on theDrawings or from the areas selected by the Contractor, subject to the approval of theEngineers Representative.

No borrow pit shall be opened until the material has been sampled in depth and approvedas suitable and written approval given by the Engineers Representative for thecommencement of the excavation. Rock and unsuitable material for filling shall not beexcavated, or if excavated by the Contractor, shall be re-deposited in the pit as instructedand shall not be measured.

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The excavation is to be done always at a minimum distance of 20.00 m from the foot of

the slope.

In extremely flat territory and in the case of soil types with a very low degree ofcompactness the distance to the foot of the slope should even be 40.00 m or according toinstructions given by the Engineer.

The Engineer will decide at the site if a borrow pit shall be established or if it is moresuitable to increase the cross section in cutting locations.

The depth of the borrow pits of the soil material might be limited with respect to theground water level, if it impedes the excavation of the material. The pits are to be set upsuch that they do not constitute any danger to people or animals. At least at the entranceand exit the pit should be so flat that climbing in and out is not difficult.

In case the soil material found in the 50 m zone are not sufficient or by other reasons theContractor has to look for other borrow places. The permissions and authorizations if anyhe might need have to be procured by the Contractor himself from the correspondingowners.

Roads for hauling the soil out of the borrow area should be provided by the Contractor.These works will not be paid as an extra payment.

Material for Embankment in Place shall be obtained from borrow areas within the Right ofWay as indicated on the Drawings or from area selected by the Contractor, subject to theapproval of the Engineers Representative.

6.11 Material

All material for the embankment shall be subject to the approval of the EngineersRepresentative. Any unsuitable material deposited in the Works shall be removed andreplaced by acceptable material by the Contractor at his own expense.

Material unsuitable for the embankment encountered in the designated borrow area may

be used as required to widen uniformly embankments, flatten slopes, to fill low places inthe right of way or for other purposes as the Engineer may direct or may be completelyrejected.

Overhaul will not be allowed and no direct payment will be made for any losses ofmaterial which may result from shrinkage compaction foundation settlement erosion



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be provided at all times. Ditches shall be maintained so as to ensure proper drainage at

all times.

6.12.1 Excavation to Formation Level

The excavation shall be carried out so as to avoid any undercutting and consequentinstability of the finished sideslope.

Should the slopes of any cutting be excavated beyond that required, the Contractor shall

make good each affected area in a manner satisfactory to the Engineer without additionalcharge.

Where excavation reveals a combination of suitable and unsuitable materials theContractor shall, unless otherwise agreed by the Engineers Representative, carry out theexcavation in such a manner that the suitable materials are excavated separately for usein the Works without contamination by the unsuitable materials. The unsuitable materialsshall be disposed of.

If with the agreement of the Engineers Representative any suitable material excavatedfrom within the site is taken by the Contractor for his own use, for instance for producingaggregates for concrete, crushed stone base or subbase for surfacing or for haul roadsor for any other purpose in or connected with the Works, sufficient suitable filling materialto occupy, after compaction, a volume corresponding to that which the excavated materialwould have occupied in embankment, shall be provided by the Contractor from his ownresources free of charge.

No suitable excavated material shall be dumped to spoil, except with the writtenpermission of the Engineers Representative, if the Contractor can show to his satisfactionthat this procedure would be economically advantageous.

Material used for haul roads shall not be reused in embankment or elsewhere without thepermission of the Engineers Representative.

Excavation shall be discontinued when climatic conditions prevent the placing of the

excavated material in embankment in accordance with the General Specification.

6.12.2 Dressing Formation Level in Rock Cuttings

Where rock or hard material is encountered at formation level in cuttings the Contractor



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6.13 Control and Disposal of Excavated Materials

The methods used in making railway and road bed excavations shall be such as they willnot shatter or loosen excavation slopes, but will leave the slopes accurately and smoothlytrimmed. As far as practicable, the materials to be excavated shall be loosened by meansof rooters and scarifies or shall be excavated without previous loosening. Such as mustbe done shall be controlled in a manner which will avoid possible shattering or looseningof materials behind the slope lines to which the excavations are to be made, as directedby the Engineers Representative. Excavated materials suitable for use in embankmentconstruction and backfilling shall be used in the construction of embankments and infilling and backfilling work as indicated on the Drawings or directed by the EngineersRepresentative.

Should the quantities of excavated materials be greater than required to construct all theembankments or other required filling and backfilling, the excess material shall be used towiden embankments uniformly or shall be otherwise disposed of as the EngineersRepresentative may direct. When excess materials are used to widen embankments

uniformly, the limits between which the embankments are to be widened with any givenquantity of excess materials shall be as the Engineers Representative directs. Excessmaterials not used in embankment widening shall be deposited at such locations and tosuch lines, grades and crosssections as the Engineers Representative may direct. Theexcavation and disposition of filling material for each, or part of each, embankment shallbe spread and compacted, in separate and clearly defined areas, for each particular kindof material as directed by the Engineers Representative.

Excavation shall not be carried out when conditions prevent the placing of the excavatedmaterials at the specific locations at which their use is desired by the EngineersRepresentative.

Any material unsuitable for use in embankment construction and backfilling shall bedisposed of in such manner as the Engineers Representative may direct. Excavatedmaterials deposed of contrary to the requirements above stated and without the consentof the Engineers Representative, shall be picked up and re-deposited as the EngineersRepresentative directs and at the Contractor s expense.

6.14 Embankment Area Preparation

Prior to placing the filling, the grubbing-up and clearing shall be performed within thegiven area the unsuitable material shall be removed and any other work shall be



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Where the height of the new embankment above the existing ground is less than 50cm

the scarified material shall be shaped and compacted as specified to the same minimumdensity as specified for the new embankment.

Where an embankment is on sloping ground of at least 1 in 4 slope, or at such otherlocations as the Engineers Representative may direct, the surface of existing groundshall be benched (in nearly horizontal steps or trenched) as shown on the Drawings,including if necessary any underdraining of the affected part of the Site.

The benching or trenches shall be kept free of water.Where the new embankment will envelop an old embankment on one or both sides, theside slopes of the old embankment shall be benched as directed by the EngineersRepresentative, and the mew fill brought up in successive layers to the level of the oldembankment before the height is increased.

Where an embankment is to be placed over an existing pavement, concrete, rock, etc.the old pavement, etc. shall be scarified and completely broken up so that all cleavageplanes are destroyed and fill material will bond properly.

Where the old pavement is of the rigid type and the depth of new embankment is lessthan one metre, the old pavement shall be completely removed and disposed of asdirected by the Engineers Representative.

6.15 Field Compaction Trials

The Contractor shall put forward in writing to the Engineer for his approval a list of theplant he proposes to use for compaction of filling in embankment and elsewhere whererequired.

The precise manner in which the earthworks are to be compacted shall be the subject offield compaction trials to establish the type, sequence and numbers of passes of thecompaction plant necessary to obtain the degree of compaction specified hereafter, theoptimum moisture content associated with such plant and the thickness of layer that may

be effectively compacted.

An area within the site selected by the Engineers Representative and approximately 20mby 20m in plan shall be stripped of any surface growth and then excavated as required bythe Engineers Representative to a depth net exceeding 0.5m. The Contractor shall thenbring in the material under trial and carry out the trial with the approved plant to establish



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6.16 Construction of EmbankmentsEmbankments shall be constructed to the lines and grades as shown in the drawings or tothe outlines specified by the Engineer.

The Contractor shall make allowance for consolidation, if any, of embankment foundationand for compaction and shrinkage of fill material, so that on completion of the earthworksthe profile of the embankment is as required.

Embankments shall be formed of suitable material as was described in the chapters 6.2to 6.6 and compacted to the standards specified in those chapters.

Embankments shall be constructed of material spread in successive layers forcompaction, each layer extending over the full width of the embankment at the height ofthe layer and the Contractor shall ensure that the required compaction is obtainedthroughout each layer, not emitting the material which after trimming will form the sideslopes. Rolling shall begin at the edge of the fill and progress toward the centre line

overlapping on successive trips by at least one half the width of the roller unit. On superelevated curves rolling shall begin at the low side and progress towards the high side.

Where materials of appreciably different characteristics are to be deposited inembankments such materials shall be spread in separate layers, each layer composed ofonly one type of material. Layers shall be reasonably levelled, or if directed, at suchcrossfalls as will shed stormwater and prevent ponding.

Fill material shall not be stockpiled in embankments and if in the opinion of the EngineersRepresentative the plant used for depositing the material does met spread the materialuniformly in a satisfactory manner, the Contractor shall employ plant to spread and gradelayers for compaction.

Earthmoving plant shall be positively controlled by the Contractor and routed ever the fullwidth of the embankment so as to ensure a degree of uniform compaction from suchplant.

The depth of each layer of filling shall suit the compaction plant and the compactionprocedure evaluated in the Field Compaction Trials, unless otherwise directed by theEngineers Representative.

Any hard material that is not broken down by the passage of the compacting plant shall



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and well packed round with finer material. This is particularly important if nondurable rock

is used.

Rockfill shall not be permitted within 40cm of formation level. Where materials of differentcharacteristics are readily available, these of relatively high bearing capacity shall beplaced in the topmost 40cm below formation.

No legs, stumps, scrub or other perishable material shall be deposited anywhere withinthe embankment.

6.17 Compaction of Earthworks

The compaction of the embankment materials shall be carried out according thespecifications given in 6.2 to 6.5. The Contractor shall, if required, adjust the moisturecontent of material spread without extra charge. Should the material be too dry, therequired amount of water shall be applied uniformly and thoroughly mixed in the soil byblading, discing or harrowing until a uniform and satisfactory moisture content is obtainedthroughout the depth of the layer. Should the material be too wet, it shall be aerated byblading, discing or harrowing until the moisture content is satisfactory. The moisture canalso be reduced by adding lime to the soil in an amount that reduces the moisture to anacceptable limit. Any soil improvement in such way has to be approved by the engineer.The Contractor shall conserve the moisture content of material excavated when this isclose to the optimum moisture content and such material shall met be stockpiled ordouble handled, but shall be spread and compacted without delay.

The Engineers Representative may order cessation of the work or further field

compaction trials if the required degree for compaction is not obtained.

The degree of compaction shall be measured in a frequency as stated in 6.7. The testingmethod shall be adequate to test to a depth of at least 1 m and shall be approved by theengineer. It is the contractors responsibility to ensure that each layer is compacted to therequired standard. Failure in doing so may result in the removal and reconstruction of theinadequate layer, even if this layer is at greater depth. The results measured shall bereported in writing to the Engineers Representative daily or when required.

No compacted layer shall be covered until approved by the Engineers Representativewho may require a compacted layer to be scarified to a shallow depth to ensure bondingwith the layer to be superimposed.

Th C t t i d i d t k t i l ti t d t i th th l th d f



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The Contractor shall provide sufficient equipment in numbers and capacity of all types

available to ensure the completion of the work according to the specifications and withinthe Contract Time.

All equipment used in the performance of the work shall comply with the definitions andrequirements and shall be subject to the approval of the Engineer or the EngineersRepresentative. It shall be maintained in satisfactory working condition at all times andsufficient reserve equipment shall be readily available to maintain the proper continuity ofall earthwork operations under all practicable working conditions.

In case of compaction of rock fill, vibrating sheep foot roller shall be used in order to crushthe rock boulders. Vibratory rollers shall be operated with their vibration mechanismoperating only at the frequency of vibration recommended by the manufacturers. All suchrollers shall be equipped with a device automatically indicating the frequency at which themechanism is operating.

Particular care is necessary in the use of compacting equipment in uniformly gradedmaterials.

6.19 Embankments at Approaches to Bridges

To avoid interference with the construction of bridge abutments and wing walls theContractor shall, at points to be determined by the Engineers Representative, suspendwork on embankments and/or cuttings forming the approaches to such structures untilsuch time as the construction of the latter is sufficiently advanced to permit thecompletion of the approaches without the risk of interference or damage to the bridge

works.

6.20 Reinstatement of Damage by Rain

Throughout the currency of the Contract all damage to completed earthworks attributableto rain and rainfall run-off or to any other cause shall be made good by the Contractorwithin 2 days of such damage occurring unless otherwise directed by the engineer.

6.21 Slips, Subsidence and Overbreaks

In the event of any slip, slide or subsidence taking place in the earthworks extendingbeyond the required profile of embankment, the Contractor shall dispose of the material inthe slip and make good as required by the Engineers Representative. The classification



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6.22 Backfill of Road bridges

The backfill of Road bridges shall be carried out as follows:

SKETCH: BACKFILLING OF ROAD BRIDGES

6.23 Backfill of Culverts

The backfill of Culverts of the RailRoad shall be carried out as follows:



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6.24 Additional Earthwork Requirements for Roads

6.24.1 General

Following additional requirements for roads shall be applicable:

6.24.2 Compaction of Earthworks for Roads

Work on compaction of materials in embankments shall only be carried out when thematerial has a moisture content within the limits agreed in the field compaction trials. TheContractor shall, if required, adjust the moisture content of material spread without extracharge. Should the material be too dry, the required amount of water shall be applieduniformly and thoroughly mixed in the soil by blading, discing or harrowing until a uniformand satisfactory moisture content is obtained throughout the depth of the layer. Shouldthe material be too wet, it shall be aerated by blading, discing or harrowing until themoisture content is satisfactory. The Contractor shall conserve the moisture content ofmaterial excavated when this is close to the optimum moisture content and such materialshall not be stockpiled or double handled, but shall be spread and compacted withoutdelay. Allowance shall be made for evaporation, for instance in excessively hot weather,by the addition of extra moisture so that compaction may be carried out satisfactorily.

The Engineers Representative may order cessation of the work or further fieldcompaction trials if the required degree to compaction is met obtained.

The degree of compaction shall be measured in each layer at least twice every 2000m2

for comparison, or more frequently as required by the Engineer s Representative.

The determination of the dry density achieved shall be performed in accordance withAASHTO T191-61 or T205-64 (cone method or balloon method), or other suitable methodsubject to the approval of the Engineers Representative, and compared with themaximum dry density as determined by AASHTO T180-74 (Modified AASHTOCompaction Test). The results so measured shall be reported in writing to the EngineersRepresentative daily or when required.

No compacted layer shall be covered until approved by the Engineers Representativewho may require a compacted layer to be scarified to a shallow depth to ensure bondingwith the layer to be superimposed.

Rolling of earth embankments shall be made at the percentages indicated in the table of



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6.24.2.1 Requirements for Subgrade Soil Compaction

Subgrade soil compaction (the active soil layer) 30cm below the formation in all parts ofthe embankment throughout the whole length and width of section shall be performed asin the Table below.

Max. Lab. Dry Weight (g/cm3) Min SubgradeCompaction (%)

Less than 1.70 Unsuitable

1.7 to 1.759 100

1.76 1.929 98

1.93 or more 95

TABLE: SUB GRADE SOIL COMPACTION

Soils with a maximum dry weight of less than 1.70g/cm3 are considered unsuitable for usein the top 300mm. Soil layer immediately below the surface of the subgrade shall bereplaced with suitable soil or granular material.

6.24.2.2 Requirements for Embankment Soil Compaction

All portions of the soil embankment throughout the total width and depth on the crosssection shall be compacted as given below.

Max. Lab. Dry Weight (g/cm3) Min Field Compaction (%)


1.44 to 1.679 98

1.68 1.759 95

1.76 1.929 92



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Max. Lab. Dry Weight (g/cm3) Min Field Compaction (%)


1.52 to 1.679 98

1.68 1.759 96

1.76 1.929 94

1.93 or more 92

TABLE: EMBANKMENTS OVER 3 M SOIL COMPACTION

The depth of compacted layer is the height by which an embankment is raised by each

successive compacted layer.

Each layer of rock used as rock fill in embankments shall be spread and levelled andsystematically compacted by at least 12 passes of a towed vibratory roller with a staticload per 2.5cm width of roll of at least 45kg or a grid roller with a load per 2.5cm width ofroll of at least 200kg or other approved plant. Where, however, the rock containssufficient soft material for satisfactory compaction to the requirements for well-gradedgranular soil the fill shall be compacted to such latter requirements. When material of

widely divergent characteristics are used in embankments and fill areas they shall bespread and compacted in separate clearly defined areas in such a manner as to complywith the requirements for railway embankments. If more than one class of material isbeing used in such a way that it is not practicable to define the areas in which each classoccurs, compaction plant shall be operated as if only the material which requires thegreatest compactive effort is being compacted.

The number of passes is the number of times that each point on the surface of the layer

being compacted has been traversed by the item of compaction plant.The thickness of the layers and the necessary number of passes or blows of compactingmeans shall suit the results of the Field Compaction Trial.

The degree of compaction shall be controlled by the number of passes or blows as



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6.25 Tolerances in Surface Levels

The finished earthworks surface unevenness when tested by a 3m straight edge, bytaking the measurement at the deepest point between two contact points of the straightedge, shall comply with the a.m. surface level tolerances.

The Contractor shall inform the Engineers Representative in a reasonable time inadvance, of the time and place of work, so as to ensure that the taking of measurements,is of the minimum inconvenience to the Engineers Representative and minimum delay for

the Contractor.

7 OVERHAUL AND EMBANKMENT IN PLACE

Overhaul will consist of performing all operations necessary for the authorisedtransportation of fill material more th