Specs for General Civil Construction_08Dec2010

8/8/2019 Specs for General Civil Construction_08Dec2010

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0 02-02-2002 Approved Issuerev. date Description/issued for prepared authorised

client: ADWEAproject: STANDARD SPECIFICATIONS FOR WATER WORKStitle: SPECIFICATION FOR GENERAL CIVIL CONSTRUCTION

tender: project: document: W-C-SS-006 rev: 0 sheet: 1 of: 20

SPECIFICATION FOR GENERAL CIVIL

CONSTRUCTION


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Client ADWEAProject: STANDARD SPECIFICATIONS FOR WATER WORKSTitle: SPECIFICATION FOR GENERAL CIVIL CONSTRUCTION


Table of Contents page

1. SCOPE...................................................................................................4

2. CODES AND STANDARDS ..................................................................4

2.1 Design of Works ..........................................................................42.2 Subsoil Investigations/Excavations/Earthworks...........................42.3 Concrete Works...........................................................................42.4 Structural Steelwork ....................................................................52.5 Painting .......................................................................................82.6 Pavements ..................................................................................92.7 Miscellaneous Works...................................................................9

3. SITE CONDITIONS................................................................................9

4. SAFETY.................................................................................................9

5. SETTING OUT .......................................................................................9

6. MAINTENANCE OF TRAFFIC FLOWS, TEMPORARY DIVERSIONS10

7. LOCATION OF EXISTING SERVICES AND THEIR SAFETY ............10

8. FIRE PROTECTION.............................................................................10

9. SCAFFOLDING ...................................................................................10

10. PROTECTION OF THE WORKS.........................................................10

11. TEMPORARY WORKS........................................................................11

12. SHOP DRAWINGS ..............................................................................11

13. WORK REASONABLY INFERRED.....................................................11

14. MATERIALS, GOODS AND WORKMANSHIP ...................................11

15. SAMPLES AND TESTING OF MATERIALS.......................................11

16. WATER AND ELECTRICITY FOR THE WORKS................................12

17. EARTHWORKS...................................................................................1217.1 General......................................................................................1217.2 Clearing and Grubbing ..............................................................1217.3 Open-Cut Excavation ................................................................13

18. TOLERANCE LIMITS ..........................................................................17


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19. SIGN BOARDS....................................................................................17

20. EXCAVATION AND BACKFILLING OF TRENCHES.........................1720.1 Excavation & Preparation Of Trench Formation ........................1720.2 Protection of Existing Services ..................................................19

20.3 Backfilling of Trenches ..............................................................19


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1. SCOPE

This specification shall be read in conjunction with all other specifications and documents

included in the Agreement between ADWEA/ENGINEER and the CONTRACTOR.

The CONTRACTOR shall be responsible for the Construction of the work taking due care tocomply with all laws, bylaws, regulations etc. issued by the Authorities.

The CONTRACTOR shall be responsible for the security of the site including his own and

Sub-Contractors work, plant, materials etc. and the safety of adjoining property, and shall be

liable for any loss or damage suffered.

The CONTRACTOR shall have deemed to have inspected and examined the work areas and

its surroundings and to have satisfied himself as to form and nature thereof including

subsurface conditions, hydrological and climatic conditions, the extent and nature of work,

and the means of access to the work areas.

No claims by way of cost or time, shall be admissible on account of non familiarity with site

conditions.

2. CODES AND STANDARDS

2.1 Design of Works

BS 6399, Part 1: Code of Practice for Dead and Imposed Loads, Part 2: Code of Practice for

Wind Loads.

2.2 Subsoil Investigations/Excavations/Earthworks

BS 5930 Code of Practice for Site Investigations

BS 1377 Methods of Tests for Soils for Civil Engineering Purposes

2.3 Concrete Works

BS 12 Specification for Ordinary and Rapid Hardening Portland Cement.

BS 63 Specification for Single Sized Aggregate for Surface Dressing.

BS 410 Specification for Test Sieves.

BS 812 Methods for Sampling and Testing of Mineral Aggregates, Sands and

Fillers.

BS 882 Specification for Aggregates from Natural Sources for Concrete.

BS 1199/1200 Building Sands from Natural Sources.

BS 1305 Specification for Batch Type Concrete Mixers.


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BS 1370 Specification for Low Heat Portland Cement.

BS 1881 Methods of Testing Concrete.

BS 3148 Methods of Tests for Water for Making Concrete.

BS 3712 Building and Construction Sealants.

BS 3797 Specification for Lightweight Aggregate for Concrete.

BS 4027 Specification for Sulphate Resisting Portland Cement.

BS 4248 Super-Sulphated Cement.

BS 4449 Specification for Hot-Rolled Steel Bars for the Reinforcement of

Concrete.

BS 4482 Hard Drawn Mild Steel Wire for the Reinforcement of Concrete.

BS 4483 Steel Fabric for the Reinforcement of Concrete.

BS 4550 Methods of Testing Cement.

BS 4551 Method of Testing Mortars, Screeds and Plasters.

BS 5075 Concrete Admixtures.

BS 5328 Methods for Specifying Concrete, Including Ready-Mixed Concrete.

BS 8004 Code of Practice for Foundations.

BS 8110 The Structural Use of Concrete.

BS 8204 In-situ Floorings.

BS EN 12878 Pigments for Portland Cement and Portland Cement Products.

BS EN ISO 4066 Specification for Bending Dimensions and Scheduling Reinforcement

of Concrete.

2.4 Structural Steelwork

BS 4 Structural Steel Sections.

BS 357 Specification for Power Driven Travelling Jib Cranes.

BS 499 Welding Terms and Symbols.

BS 709 Methods of Destructive Testing Fusion Welded Joints and Weld Metal

in Steel.


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BS 1290 Specification for Wire Rope Slings and Sling Legs for General Lifting

Purposes.

BS 1757 Specification for Power Driven Travelling Mobile Cranes.

BS 2573 Rules for the Design of Cranes.

BS 2853 Specification for the Design and Testing of Steel Overhead Runaway

Beams.

BS 2994 Specification for Cold-Rolled Steel Sections.

BS 3125 Specification for Power Driven Hoists for Materials.

BS 3243 Specification for Hand Operated Chain Blocks.

BS 3692 Isometric precision hexagon Bolts, Screws and Nuts.

BS 4018 Specification for Pulley Blocks for Use With Wire Roper for Maximum

Lift of 25 ton in Combination.

BS 4190 Specification for ISO Metric Black Hexagon Bolts, Screws and Nuts.

BS 4278 Specification for Eye Bolts for Lifting Purposes.

BS 4320 Metal Washers for General Engineering Purposes.

BS 4395 High-Strength Friction Grip Bolts.

BS 4429 Specification for Rigging Screws and Turn Buckles for General

Engineering Lifting Purposes and Pipe Hanger Applications.

BS 4465 Specification for Design and Construction of Electric Hoists for both

Passengers and Materials.

BS 4536 Specification for Heavy Duty Pulley Blocks for use with Wire Rope.

BS 4592 Industrial Type Metal Flooring, Walkways and Stair Treads.

BS 4604 Specification for the Use of High Strength Friction Grip Bolts inStructural Steelwork.

BS 4620 Rivets for General Engineering Purposes.

BS 4870 Specification for Approval Testing of Welding Procedures.

BS 4871 Specification for Approval Testing of Welders Working to Approved

Welding Procedures.


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BS 4872 Specification for Approval Testing of Welders When Welding

Procedure Approval is not Required.

BS 4898 Specification for Chain Level Hoists.

BS 5135 Specification for Arc Welding of Carbon and Carbon ManganeseSteels.

BS 5395 Stairs, Ladders and Walkways.

BS 5594 Specification for Leaf Chains Clevises and Sheaves.

BS 5744 Code of Practice for Safe Use of Cranes.

BS 5950 Structural Use of Steelwork in Building.

BS 6210 Code of practice for Safe Use of Wire Rope Slings for General Lifting

Purposes.

BS 6323 Specification for Stainless and Welded Steel Tubes for Automobile,

Mechanical and General Engineering.

BS 6443 Penetrant Flow Detection.

BS 6521 Guide for Proper Use and Maintenance of Calibrated Round Steel Link

Lifting Chains.

ISO 8504 Surface Finish of Blast Cleaned Steel for Painting.

BS 7212 Code of Practice for Safe Use of Construction Hoists.

BS 7668 Specification for Weldable Structural Steel.

BS EN 287 Approval Testing of Welders Working to Approved Welding Procedures

- Fusion Welding of Steel.

BS EN 288 Approval Testing of Welding Procedures - Fusion Welding of Steel.

BS EN 499 Welding Consumables

BS EN 571-1 Penetrant Testing of Welded or Braced Joints.

BS EN 970 Non Destructive Examination of Fusion Welds.

BS EN 10025 Hot Rolled Products of Non-alloy Structural Steel.

BS EN 10029 Specification for Tolerances on Dimensions, Shape and Mass for Hot

Rolled Steel Plates.

BS EN 10056 Specification for Structural Steel Equal and Unequal Angle.


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BS EN 10113 Hot-rolled Products in Weldable Fine Grain Structural Steels.

BS EN 10155 Structural Steels with Improved Atmospheric Corrosion Resistance.

BS EN 10210 Hot Finished Structural Hollow Sections of Non-alloy and Fine Grain

Structural Steels.

BS EN 13246 Specification for Tensional Steel Strapping.

BS EN 13394 Specification for Non-Metallic Tensional Strapping.

BS EN ISO 12944 Code of Practice for Protective Coating of Iron and Steel Structures

Against Corrosion.

BS EN ISO 1461 Specification for Hot-Dip Galvanized Coatings on Iron and Steel

Articles.

2.5 Painting

BS 381 C Colours for Specific Purposes.

BS 1070 Black Paint (Tar Based).

BS 2523 Lead-Based Priming Paints.

BS 3900 Methods of Tests for Paints.

BS 4800 Paint Colours for Building Purposes.

BS 4904 Specification for External Cladding Colours for Building Purposes.

BS 5252 Framework for Colour Coordination for Building Purposes.

BS 6150 Code of Practice for Painting of Buildings.

BS 6477 Specification for Water Repellants for Masonry Surfaces.

BS 6900 Linseed Oil for Paints.

BS 6949 Specification for Bitumen Based Coating for Cold Application ExcludingUse in Contact with Potable Water.

BS 7079 Preparation of Steel Substrates before Application of Paints and

Related Products.

BS 7664 Specification for Undercoat and Finishing Paints.

BS 8202 Coatings for Fire Protection of Building Elements.

BS EN ISO 2064 Metallic and Other Non-organic Coatings.


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BS EN ISO 12944 Code of Practice for Protective Coating of Iron & Steel Structures

against corrosion.

2.6 Pavements

BS 7263 Precast Concrete Flags, Kerbs, Channels, Edging and Quadrants.

BS 7533 Precast Concrete Paving Blocks.

BS EN 515 Aluminium and Aluminium Alloys, Wrought Products.

2.7 Miscellaneous Works

BS 476 Fire Tests on Building Materials and Structures.

BS 743 Materials for Damp Proof Courses.

BS 5588 Fire Precautions in the Design and Construction of Buildings.

3. SITE CONDITIONS

Refer clause 3.0 in Specification for General Technical Requirements.

4. SAFETY

All CONTRACTOR's works shall be performed in accordance with best safe practices for

activities to be undertaken during construction.

Detailed method statements for each activity to be undertaken shall be prepared by theCONTRACTOR inclusive of all proposed safety measures for submission to gain approval by

ADWEA/ENGINEER which must be obtained prior to the start of the activity concerned.

All CONTRACTOR's personnel shall be subject to safety training.

All CONTRACTOR's personnel shall be suitably trained to perform activities and in the safe

use of all equipment to be operated.

5. SETTING OUT

The CONTRACTOR shall employ experienced Land Surveyors to carry out all surveying andsetting out work. The CONTRACTOR will establish the lines and levels of the works prior to

commencement of works.

In order to establish the existing ground levels over the areas of the works, the

CONTRACTOR shall establish a grid over the site and agree the levels, grading etc. and final

levels required with ADWEA/ENGINEER.

The CONTRACTOR shall also check the accuracy of the Survey drawings etc. given to him

and notify ADWEA/ENGINEER of any Discrepancy whatsoever.


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Before commencement of Works, the CONTRACTOR shall prepare and seek approval from

ADWEA/ENGINEER of all Connection Designs and Shop Drawings pertaining to the work.

The CONTRACTOR shall also carry out all dimensional and setting out checks on the

construction items as may be required by the technical sections of interdisciplinary

specifications of the contract.

Any and all discrepancies found during these checks shall be noted and brought to the

attention of ADWEA/ENGINEER with their significance to the works clearly highlighted.

6. MAINTENANCE OF TRAFFIC FLOWS, TEMPORARY DIVERSIONS

The necessity for, provision of, details of and maintenance of Temporary road diversions and

existing road closures shall be subject to the approval of ADWEA/ENGINEER and the

Federal Traffic Police. No Public or Private facility shall be stopped or interrupted without the

written permission of ADWEA/ENGINEER. Such permission will not be given until suitable

permanent or temporary alternatives approved by ADWEA/ENGINEER have been providedby the CONTRACTOR.

7. LOCATION OF EXISTING SERVICES AND THEIR SAFETY

Before commencing construction work the CONTRACTOR shall locate the routes and identify

all services in the Area.

Preliminary excavation to locate services shall be by hand or hand tools.

The CONTRACTOR shall take any and all measures reasonably required by any Public or

any Statutory Authority for the support and full protection of all mains, pipes, cables and otherapparatus during the progress of the works, and shall construct and provide to the satisfaction

of ADWEA/ENGINEER, all works necessary for the prevention of damage or interruption of

services.

8. FIRE PROTECTION

Adequate precautions shall be taken against fire through all CONTRACTORS and Sub-

Contractors operations.

Construction Practices, including cutting and welding, and protection of adjacent materials

during construction shall be in accordance with good standard practices for such work.

9. SCAFFOLDING

The CONTRACTOR shall provide, erect, maintain, dismantle and clear away at completion

proper and adequate scaffolding including that required for Sub-Contractors and Specialists.

10. PROTECTION OF THE WORKS

The CONTRACTOR shall wherever required or directed by ADWEA/ENGINEER cover up

and protect the works from the weather and from damage by his own or other workmen


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performing subsequent operations. He shall provide necessary dust sheets, hoardings,

barriers, guardrails etc. and clear away same at completion.

11. TEMPORARY WORKS

The CONTRACTOR shall furnish to ADWEA/ENGINEER full particulars, drawings,calculations, etc. of all temporary works necessary for the execution of the works and shall

allow sufficient time for ADWEA/ENGINEER to consider the same. The CONTRACTOR shall

be solely responsible for the stability and safety of all temporary and unfinished permanent

works.

The CONTRACTOR shall properly uphold the sides of excavations and shall provide all

necessary timber planks and struts and/or temporary sheet piles. Stability calculations for

same shall be submitted to ADWEA/ENGINEER for approval.

The CONTRACTOR shall provide all necessary temporary supports to pipes, cables and the

like throughout his works. Stability calculations for such shall be submitted toADWEA/ENGINEER for approval.

12. SHOP DRAWINGS

The CONTRACTOR shall furnish ADWEA/ENGINEER with shop drawings which he shall

require -detailing materials, layouts, sizes, dimensions, etc. clearly. No such work shall be put

in hand until ADWEA/ENGINEER's approval of shop drawings has been obtained in writing.

13. WORK REASONABLY INFERRED

The CONTRACTOR shall execute the work in accordance with the intent and meaning ofspecifications and drawings and shall supply all accessories and other items essential for the

proper execution of the work and shall execute all work which may be reasonably inferred

whether or not specifically shown or described.

14. MATERIALS, GOODS AND WORKMANSHIP

The whole of the workmanship, goods and materials incorporated in the works shall be new

and of the best quality available and shall be to the approval of ADWEA/ENGINEER.

Should ADWEA/ENGINEER discover on the works any materials other than those approved,

they may order their removal from site. Removal of these unapproved materials from site is tobe done at the expense of CONTRACTOR.

15. SAMPLES AND TESTING OF MATERIALS

Prior to ordering or delivering any materials or manufactured item to site, the name and

address of the Supplier and, where required by ADWEA/ENGINEER, adequate samples,

sample schedules and Manufacturer's certificates for all the materials and goods to be used

in the works shall be submitted to ADWEA/ENGINEER for approval.


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16. WATER AND ELECTRICITY FOR THE WORKS

The CONTRACTOR shall provide water and electricity for the works including that required by

the sub-contractors and provide all necessary temporary work.

Importing water by tanker and storing on site shall be allowed for by the CONTRACTOR.

Temporary electricity generating equipment, should this prove necessary, shall be allowed for

by the CONTRACTOR.

17. EARTHWORKS

17.1 General

The CONTRACTOR shall, before commencing any excavation, grading or fill, survey and

take levels on the original ground surface and correlate same with all drawings made

available to him. He shall then prepare plans and sections accordingly which should bemutually agreed and signed by ADWEA/ENGINEER and CONTRACTOR as truly

representing the configuration of the areas in question at the commencement of work.

17.2 Clearing and Grubbing

17.2.1 General

This work shall consist of clearing and grubbing the area of the work within the limits of the

Site and as ordered by ADWEA/ENGINEER of all debris, refuse, vegetation, demolition debris

and other deleterious material.

17.2.2 Execution of Work

The CONTRACTOR shall perform the work of clearing and grubbing so as to remove the

material herein specified and if he wastes material suitable for incorporation into or for use on

the work, the amount of suitable material shall be replaced by the CONTRACTOR at his

expense. All material removed by the clearing and grubbing operation shall be transported

from the site or otherwise disposed of as specified or directed by ADWEA/ENGINEER.

With the exception of areas to be excavated, all depressions made below the ground surface

by the removal of rubbish or existing works shall be refilled with suitable material and

compacted to the satisfaction of ADWEA/ENGINEER.

Grading or excavation operations shall not be started in any areas until clearing and grubbing

within the area affected have been completed.

Fences, upon or within the limits of the works and not necessary for the construction shall be

removed carefully by the CONTRACTOR wholly or in part as specified or directed. The

materials so removed shall be piled neatly and in an acceptable manner or otherwise

disposed of as specified or directed by ADWEA/ENGINEER.


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17.2.3 Auxiliary Works

Unless otherwise specified, all and any kind of works materials services, safety measures,

etc., as well as, and if so requested by ADWEA/ENGINEER all tests and samples required for

the completion of the work shall be included in the offer.

17.3 Open-Cut Excavation

17.3.1 General

Survey points, bench marks, boundary stones and the like shall not be removed without

ADWEA/ENGINEER's written consent.

Removed boundary stones and markings shall be stored according to ADWEA/ENGINEER's

instructions.

Extra bench marks to be provided by the CONTRACTOR shall be furnished with a plate,approximately 25 x 25 cm in size, with the bench mark inscription painted in black letters on a

light background with clearly legible weatherproof oil paint.

For all fill and cut over 1.00 m in height, sturdy stakes shall be placed at any change of

direction of the ground but in all cases at intervals no greater than 30 m as directed by

ADWEA/ENGINEER.

Excavations in sand shall be to a slope of 1:3, one vertical to three horizontal. If any

permanent slope is to be kept in the sand it shall be stabilized by one of the following means,

- 150 mm of compacted gatch

- Cement/sand mixture

- Bituminous/cement mixture

- Precast concrete paving tiles

The quantity, type and capacity of the equipment provided, the work method envisaged,

transportation and distribution of the excavated materials, location of stock-piles, main

storage areas as well as the approximate number of labourers, etc. and the working schedule

and any amendment to it during the construction period shall require ADWEA/ENGINEER's

prior approval.

Bottom and slopes of open-cut excavations on which concrete is to be placed shall be

finished exactly according to the established lines and slopes. To avoid loosening of the soil,

heavy equipment such as bulldozers or power shovels shall not operate within 10 cm of the

final lines of the excavation bottom. The last 10 cm shall be excavated by means of hand

tools.


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17.3.2 Safety Measures

The CONTRACTOR shall be responsible for all necessary safety measures. From the

commencement of the work until acceptance, the CONTRACTOR shall strictly follow the

safety regulations in order to prevent accidents.

Proper strutting, sheeting and bracing, including re-arrangement of the installations when

necessary, protection of slopes, methods of excavation to reduce risk of slides, etc., shall be

for the responsibility of the CONTRACTOR. In the event of soil slides occurring during earth

and rock work, all damage shall be made good by the CONTRACTOR.

Where the nature of the soil gives reason to fear any drifting, initial excavation operations

shall be carried out with special care.

Excavation shall not be carried out below existing building foundations, if any, until shoring to

be performed by the CONTRACTOR has been completed. All existing structures,

foundations, pipes and cables, if any, which are to be incorporated into the final work shall beadequately protected or replaced by the CONTRACTOR.

17.3.3 Over-excavation

If somewhere, and for any reason, excavations are executed beyond the established lines

and without ADWEA/ENGINEER's previous approval, the CONTRACTOR shall backfill with

lean concrete or other approved material, the volume corresponding to the over excavation at

his own expense.

17.3.4 Stockpiles and Disposal

Excavation material from the works selected by ADWEA/ENGINEER for use shall be placed

in its final position, if possible, or otherwise may be stockpiled or deposited on site as directed

by ADWEA/ENGINEER.

Only the stockpiling of rock, gravel and other non-cohesive materials to be used for

permanent work will be permitted. In no case shall the stockpiling of silt or disintegrated rock

to be used in structural fills be permitted.

Spoil unfit for re-use shall be removed by the CONTRACTOR to sites approved by

ADWEA/ENGINEER and shall not be permanently deposited other than on such sites. The

CONTRACTOR shall trim and form the edges of soil to profiles and levels as directed byADWEA/ENGINEER. He shall also maintain without interruption the flow of water courses

affected by the disposal of spoil materials and he shall observe any agreement concerning

the site existing between the employer and other personnel or authorities concerned.

The placing of materials within the waste areas shall be made in layers not exceeding 0.50 m

in thickness in order to obtain an appreciable degree of compaction by means of the

transportation equipment. All traffic towards or from the waste areas shall be continuously

directed and changed for the total covering of the surface of such areas in order to take

advantage of the weight of vehicles for compaction.


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The waste areas and disposal of the excavated materials shall be subject to

ADWEA/ENGINEER's approval. Waste areas shall be located in those places where, in

ADWEA/ENGINEER's opinion, they do not interfere either with the natural flow of water or

with future structures and where they can not impair the general appearance of the completed

structures or impede access to the different structures.

The CONTRACTOR shall transport materials from the excavations to their final destination

whether in the work or in the waste areas, including any necessary temporary stockpiling and

the additional loading and transporting operations.

17.3.5 Backfilling

Foundations and structures shall be backfilled with approved material compacted in layers by

suitable equipment until maximum density has been obtained to the satisfaction of

ADWEA/ENGINEER. Compacting shall be carried out with special care by means of

pneumatic or mechanical tampers of a type previously approved by ADWEA/ENGINEER to

avoid damage to structures.

Areas to be backfilled will be prepared so as to obtain a soil density at least equal to 95

percent of Modified Proctor test (ASTM D 1557).

This preparation may be suppressed by ADWEA/ENGINEER if ground quality makes it

superfluous.

Unless otherwise specified, backfilling density shall not be less than 95% of the maximum

density obtained by the Modified Proctor test (ASTM D 1557).

The thickness of loose fill layers shall not exceed 300 mm unless the CONTRACTOR provesto the satisfaction by test beds that the equipment and method of compaction exceeds the

required density.

Surfaces receiving fill layers shall, if smooth, be previously scarified to obtain a good key

between the new fill layer and the subgrade.

Fill shall not be deposited under water without ADWEA/ENGINEER's permission. This

permission will not normally be granted for cohesive soil or for fill of any kind where the

standing water, in the opinion of ADWEA/ENGINEER, can be pumped out or diverted.

Permission may be granted to place rock fill by random dumping in areas where the depth of

water is greater than 30 cm but the methods and quality of the fill material shall be subject toapproval and when the fill level is 50 cm above the water surface it shall be compacted until

there is no discernible movement under the equipment used for placing or compacting fill.

Thereafter, normal backfilling and compaction shall be resumed.

Where swamps, bogs or other similar wet areas have to be traversed by the works, they shall

be drained as directed by ADWEA/ENGINEER according to the materials and conditions

encountered. Prior to the formation of embankments, fills, etc., any unsuitable materials

occurring on the site shall be removed to such depths and widths as may be directed by

ADWEA/ENGINEER and approved excavations shall be properly backfilled with suitable and

approved excavated materials and shall be deposited and compacted to the satisfaction of


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ADWEA/ENGINEER. Similarly, soft or weak spots encountered will be removed and, as with

any voids, will be backfilled as specified.

17.3.6 Test and properties

The control of working and tests operations will be carried out by ADWEA/ENGINEER withthe full assistance of the CONTRACTOR.

The CONTRACTOR will prepare sheets for statistical analysis of the field and laboratory tests

as required in accordance with the respective ASTM or BS requirements.

Field density tests in accordance with BS 1377 will be required to be carried out by the

CONTRACTOR at each successive layer of fill at a sampling rate determined by

ADWEA/ENGINEER.

17.3.7 Auxiliary works

The auxiliary works comprise, but are not necessarily limited to the following :

- removing and storing of boundary stones, bench marks, etc., protection of surveying

points - designations by means of boards -survey and protection of all secondary survey

points, profiles, etc.

- difficulties to be overcome where excavation may have to be carried out in layers.

- keeping off or diversion of water, including any pumping required, difficult work caused

by water, etc.

- removal of any groynes, buried pipes, fascines and the like that might interfere with

excavation profiles, irrespective of whether or not such structures are specified.

- overcome difficulties resulting from the Specifications relating to filling, compaction tests,

eliminating unsuitable material from filling, and if necessary, mixing of different soil

materials.

- transport of excavated material to fill or deposit, placing and spreading in layers

according to conditions and drawings, and careful compaction.

- overcome difficulties in transport due to existing ground conditions.

- sorting of excavated materials which, if necessary, are to be used for special purposes.

- providing, maintaining and later removing access ways - maintaining existing ways and

roads - providing, placing, maintaining and later removing, conveying and dumping

materials and/or equipment that might be required.


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18. TOLERANCE LIMITS

The tolerance limits for the permanent finished earthworks will be as follows:

Horizontal dimensions will be within +75 mm and -75 mm of the true dimensions shown on

the approved drawings.

For slopes to embankments or cuttings the horizontal deviation between the top and bottom

of the slope will be within +5% and -5% of the true horizontal component of the slope shown

or calculated from the approved drawings.

Formation levels shall be within 0 mm and -25mm of the true levels shown on drawings.

Other earthworks levels shall be within +05 mm and -50 mm of the true levels shown on the

approved drawings.

19. SIGN BOARDS

The CONTRACTOR shall provide and erect adequate number of sign posts at locations

directed by the concerned Department of ADWEA/ENGINEER. The size of the display

boards shall be 2000 deep x 1200 wide or as directed by the concerned Department of

ADWEA/ENGINEER. Minimum size of board shall be 500 deep x 800 wide.

The signboards shall carry the names of the project CONTRACTOR, the ADWEA and the

ENGINEER with logos including the particulars of the local site.

A single post of 76.2 mm dia. MS pipe shall be used for sign boards of 500 x 800 size. For

larger boards two posts of 76.2 mm dia MS pipe shall be used.

The supports shall be epoxy coated with a top coat of polyurethane in grey colour.

Appropriate signs and notices etc. shall be written, by a skilled sign writer, in English and

Arabic, to the approval of ADWEA/ENGINEER.

20. EXCAVATION AND BACKFILLING OF TRENCHES

20.1 Excavation & Preparation Of Trench Formation

The CONTRACTOR in carrying out excavation for trenches shall, where required, erect and

maintain an approved type of temporary fencing around any work and shall provide fenced

access ways across the trenches.

The CONTRACTOR shall ensure that all excavation and timbering is carried out in a careful

manner, that it is rendered secure and safe, and that all measures necessary are taken to

prevent the removal or falling in of material beyond the trench dimensions detailed. The

CONTRACTOR shall maintain all timbering until the completion of the work to the satisfaction

of ADWEA/ENGINEER and shall promptly remove any material which has caved into the

excavation.


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ADWEA/ENGINEER may direct the CONTRACTOR to protect his excavation with timbering

where, in his opinion, such timbering is necessary to ensure that safety of the workmen,

adjoining structures and work generally. Any action taken by ADWEA/ENGINEER in this

regard will in no way relieve the CONTRACTOR of any responsibility or liability under the

Contract.

A clear space shall be left between the edge of the excavation and the inner toes of the spoil

banks, to the approval of ADWEA/ENGINEER.

No back-throwing whatever shall be allowed and all materials shall be brought to the surface

and formed in heaps clear of the excavation.

The material excavated in trenches shall, if unsuitable, be removed from site and shall be

replaced with suitable material.

Unsuitable material shall include :

- Materials from swamps, marshes and bogs

- Materials susceptible to spontaneous combustion

- Stumps and perishable material

- Clays of liquid limit exceeding 40%

- Plasticity index exceeding 11%

- Excessively wet materials

All surplus and unsuitable excavated material shall be carted to the approved tip.

The bottom of the trench shall be accurately graded. Care shall be taken not to excavate

below the depths indicated. Where rock is encountered, the rock shall be excavated to the

required depth. Uneven surfaces of the bottom of trench shall be excavated 150mm deeper.

Such depth in rock shall be backfilled with approved fill material and compacted as specified

and/or as directed by ADWEA/ENGINEER.

Whenever unsuitable soil is encountered which in the opinion of ADWEA/ENGINEER is to be

removed, it shall be removed to the depth required and the trench backfilled to the proper

grade with approved fill material and compacted.

The width and depth of the trenches for electrical and telephone cables/ducts shall be as

specified in the relative drawings or as ordered by ADWEA/ENGINEER. Banks may be

sloped or widened to facilitate placement of cables, but not to an extent that will cause

interference with other utilities and structures. No battering of trenches shall be allowed under

existing carriageways, unless otherwise agreed by ADWEA/ENGINEER.


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20.2 Protection of Existing Services

Where new cable ducts are to be laid alongside, over or under the existing, the

CONTRACTOR shall take care to interfere as little as possible with the existing services and

connections thereto and any damage shall be repaired by the CONTRACTOR to the approval

of the appropriate Authority or by the appropriate Authority at the cost of the CONTRACTOR.

The CONTRACTOR shall make all arrangements for protecting existing services and for

temporarily diverting them to maintain the services without interruption.

Existing services, pipes, mains, ducts, etc., exposed in trenches for new work shall be

protected in accordance with the requirements of the relevant Authority before trenches are

refilled.

The CONTRACTOR shall lay cables, fittings, specials, etc., under hedges, fences, walls, etc.,

as necessary.

Where hedges are damaged or destroyed the whole shall be restored and reinstated with

shrubs of the same kind as the hedge, planted in due season in an approved manner and

fenced or otherwise protected as required by ADWEA or occupiers and the ENGINEER.

Where fences or walls are damaged or destroyed the whole shall be restored and reinstated

with like materials to the satisfaction of ADWEA or occupiers and the ENGINEER.

The CONTRACTOR shall ensure that no trees are damaged or permanently removed in

carrying out the Contract except where directed due to the presence of permanent works and

approval is given by the relevant Authority.

20.3 Backfilling of Trenches

Trench refilling shall commence with approved fill in compacted layers not exceeding 200 mm

thick, each layer being well compacted by hand with iron rammers weighing not less than 5

kg, until the trench has been filled to a height of 300 mm above the top of the materials e.g.

cables/ducts etc.

The remainder of the trench shall then be refilled in compacted layers not exceeding 200 mm

in thickness, each layer being well compacted with power rammers, vibrating plate

compactors or other mechanical means of a type to be approved until the ground is

thoroughly consolidated up to the required level for surface reinstatement. Each layer shall becompacted to 95% of its maximum dry density, should the quantity of the excavated materials

be not sufficient, due to unsuitability or otherwise, for the process of backfill and fill, the

CONTRACTOR shall obtain the quantity required of such backfilled and fill from approved

borrow pits and transport same to the site of work at his own expense.

Trenches shall not be backfilled until all required tests are performed and until

ADWEA/ENGINEER has verified that the materials e.g. cables/ducts etc. have been installed

in accordance with the specifications and drawings.


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Lumps and clots shall be broken up before use. Materials shall not be dropped from a height

and where directed water shall be added to assist in adequate consolidation.

Where cover to materials e.g. cables/ducts is less than 400 mm, or where ordered by

ADWEA/ENGINEER, protection in the form of concrete encasing shall be provided according

to an approved drawing or as ordered by ADWEA/ENGINEER.

Specs for General Civil Construction_08Dec2010

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