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WAM

Client: FEDERAL ELECTRICITY AND WATER AUTHORITY (FEWA) Project: STANDARD SPECIFICATIONS FOR WATER WORKS

Engineer WATER DIRECTORATE - ASSET MANAGEMENT DEPARTMENT

Title: Technical Terms / Chapter-4 / Engineering Specifications / Civil Engineering Works Specification

CS10-PILING WORKS

Office:

DUBAI Order:

Document: MWA_PRO_07/WAM-04-CS10 Rev: OCT/2014 sheet: 1 of: 19

Federal Electricity & Water Authority

Water Directorate

Asset Management Department

STANDARD SPECIFICATIONS

FOR WATER WORKS

TECHNICAL TERMS

Chapter – 4

Engineering Specifications

[C-Civil Engineering Works Specifications]

CS10-Piling Works

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CS10-PILING WORKS

Office: DUBAI Order: Document: MWA_PRO_07/WAM-04-CS10 Rev: OCT/2014 sheet: 2 of: 19

CS10-Piling Works

TABLE OF CONTENT

1. GENERAL

2. APPLICABLE STANDARDS AND RECOMMENDATIONS

3. PILES CHARACTERISTICS AND DESIGN CRITERIA

4. DESCRIPTION OF WORK

5. DOCUMENTS TO BE SUBMITTED

6. MATERIALS

7. QUALIFICATION

8. PROGRAMME

9. STAKING OUT - TOLERANCES

10. CUT- OFF

11. WORKING PLATFORM

12. REJECTION

13. BORED CAST-IN-PLACE PILES

13.1 Boring and Casing

13.2 Anchorage in the Rock

14. STEEL REINFORCEMENT

15. CONCRETE

15.1 Composition

15.2 Concreting

15.3 Concrete control

16. PILING RECORD

17 PILE TESTING (TYPE TESTS):

17.1 General

17.2 Proof Load (Routine) Test

17.3 Static Load Test

17.4 Pile Integrity Test

17.5 Dynamic Testing

17.6 Guidelines for Testing

17.7 Tolerances

18. PREPRODUCTION PILES

19. DRIVEN PILES

20. PILE FOUNDATION DESIGN

21. SUBMITTALS

22. SAFETY

23. SETTING OUT

24. EXECUTION

25. BENTONITE

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CS10-Piling Works

1. GENERAL

These Specifications cover the requirements for the materials, the installation and the execution of bored cast- in place concrete piles. The Contractor shall submit the complete method statement for his proposed piling method and the pile testing works, including type of piles, working loads, diameters, proposed, detailed installation procedure and all required specifications.

2. APPLICABLE STANDARDS AND RECOMMENDATIONS

The piling works and design shall be in accordance with the latest editions of British and American

Standards; especially DIN 4114 Bored cast-in-situ piles 1054/A1 Subsoil, Subsoil - Verification of the safety of earthworks and foundations BS 4449) BS 4461) {For reinforced concrete} BS EN ISO 3766:2003) BS 8500-1:2006)

BS 8008 Code of practice for safety precautions in the construction of large diameter boreholes for piling and other purposes

BS 5930 Code of practice for Site investigation BS 6031 Code of practice for earthworks BS EN 1997-1:2004 Geotechnical design. General rules ASTM D1143 Method of testing, Piles under static axial compressive load.

Recommendations No.250 of Building Research Establishment Digest "Concrete in sulphate-

bearing soils and groundwater".

Standards shall include all the latest revisions.

Other internationally accepted standards, which ensure a quality equal to or higher than the standards mentioned above, can be submitted for the approval of FEWA but only if these are submitted in the English language edition. If any standard contains a provision, which is inconsistent with a provision in another standard, the more stringent shall apply.

3. PILES CHARACTERISTICS AND DESIGN CRITERIA

The bearing capacity of the driven/bored cast-in-situ piles shall be defined by using a minimum of

two static formulae, based on standard penetration test (SPT and soil tests), and, in addition to the static formula, dynamic formula shall be used for estimating the bearing capacity of the driven cast-in-situ piles.

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Pile load tests shall normally be carried out for pilot, nonworking and working piles to confirm the results of the static and dynamic loading as well as to define the expected settlement under the working load.

A temporary steel casing shall be provided for all piles from their cut-off levels as far as the rock

or consolidated soil formation for loose strata and for moderate to hard strata, temporary steel casing shall be provided at top portion only as approved by FEWA. Under adverse soil conditions the use of a permanent casing must be considered by the Contractor.

The working loads shall take into account the negative skin friction induced by the soil. The Contractor shall provide the final design of the piles with regards to the diameters, capacities

and depths after the results of the required soil investigations. The calculation note shall include a slenderness control.

4. DESCRIPTION OF WORK

Mobilization of all equipment;

Preparatory works, the installation of the working Site and all the temporary works requested for the boring of the piles using a temporary casing.

Steel reinforcements and approved plastic spacers to maintain the concrete cover as required;

Concreting;

Cut-off;

Pile tests;

Tests on the materials and the piles and any soil testing, as may be required by FEWA/Engineer;

Inventory of fixtures, its costs and the costs resulting from any damage caused by pile execution;

Cleaning of the Site

Demobilization of all equipment. 5. DOCUMENTS TO BE SUBMITTED

The following documents shall be submitted by the Contractor to FEWA/Engineer in due time and are to be approved before starting the piling works:

o References concerning pile foundations carried out by the Contractor/ Sub-

contractor for similar structures and soil conditions, list of qualified staff o Detailed descriptions of the plant, equipment, materials and procedures

proposed for each type of piling operations that is to be undertaken; these descriptions will include Plant and Equipment Specifications, casing and sleeve systems, detailed construction or installation procedures, tests procedures

o A proposal of pile record book and pile record sheets

o Number and location of the piles,

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o Working loads acting on the piles, o Bearing pressures, settlements, horizontal displacements of the piles (isolated

pile and group of piles),

o The “useful" length of the piles with cut-off level and base level,

o Diameters of the piles,

o Steel reinforcement of the piles,

o Sequence of piling for each part of the works.

o General programme of the piling works.

6. MATERIALS

Specifications for cement, aggregate, water, admixture, reinforcement and concrete of Clause 7 “Concrete and Reinforcement” shall apply to this specification of piling works.

The origin and quality of steel reinforcement, cement, aggregates, mix water, grouting and

admixtures, will be approved by FEWA/Engineer and shall conform to all applicable standards. a) OPC/MSRPC Sulfate-Resistant Cement: BS 4027 b) Standard Plasticizing and normal water reducing agent: BS5075: Part 1: 1982 c) Superplasticizing: ASTM C494 (F & G) d) Reinforcement: ASTM A165 or BS 4449. Required yield strength shall be 460

N/mm2

Note: For concrete placed by Tremie pipe under bentonite slurry/temporary casing, use

superplasticizing agent with slump exceeding 150mm but not more than 180mm.

7. QUALIFICATION The piles installation shall be undertaken using proven techniques and equipment and

implemented by specialist personnel who have extensive experience in carrying out such work. The Contractor shall provide qualified personnel i.e. a foreman for every piling crew, who shall always be present during the works, under the guidance of FEWA/Engineer.

8. PROGRAMME

The programme of piling will be submitted for the approval of FEWA/Engineer four weeks before

the start of the piling works. In these documents, the Contractor shall propose the sequence of piling.

Three working days before the end of each week, the Contractor shall submit to FEWA/Engineer the detailed piling programme for the next week, including adequate notice of his intention to work outside normal hours and at weekends.

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When a modification occurs in the programme, he shall immediately inform FEWA/Engineer. No modifications of the programme can be made without FEWA/Engineer’s approval, except those agreed at the beginning of the works.

9. STAKING OUT – TOLERANCES

The landmarks to be used for the implementation of the piles must be effective, solid and well

protected. The method of location of the piles is a duty of the Contractor. The settling out has to be carried out from the main grid lines of the proposed structures.

The maximum allowed deviation of the piles centre from the theoretical location shown on the setting out drawing is 50 mm in any direction. The maximum permitted deviation of the completed pile from the vertical is 20 mm per meter (2.0%).

10. CUT- OFF

The piles are concreted up to a minimum level of 70 cm above the lower pile cap surface, which

means 60 cm above the cut-off level. The cut-off must eliminate all polluted or poor characteristics concrete at the top of the pile and be

carried out over a height of minimum 10 cm in sound concrete. When this sound concrete is found below the cut- off level, the Contractor must realize, at his own expenses, a new concreting up to the cut-off level with a full connection to the pile. Any repairing must be approved by FEWA/Engineer.

The concreting of the pile caps may start only after the cut- off the pile and after obtaining a

satisfactory resistance of the pile concrete. The cut-off using a concrete breaker must be carefully performed according to a method approved

by FEWA/Engineer. The concrete in the head of the pile shall be carefully broken away from the reinforcement, which shall then be cleaned and bent as shown on the drawings or as directed. The concrete surface at the cut-off level shall be horizontal, plane and free from all loose aggregate.

11. WORKING PLATFORM

The Contractor shall provide a well-designed working area which allows namely the machines

circulation, the easy removal of the boring soils and slurries, the handling and the stock-piling, in good condition, of the prefabricated reinforcement cages.

The areas where piling operations are to be carried out shall be leveled and kept clear of water to

provide a dry stable working platform for the plant and equipment operation. After completion of the piling works the Project Site shall be cleaned and all excavated material

due to these works shall be removed by the Contractor.

The level of the working platform from which the piles are executed shall always be located at one meter minimum above the highest static level of the ground water.

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12. REJECTION

If a pile is rejected by FEWA/Engineer, the Contractor has to replace it by others in the vicinity of the rejected pile on instruction of FEWA and at no expense to the Contract.

The Contractor shall bear the cost of:

Re-design of pile caps;

Extra cost of construction involved due to unsatisfactory or incorrectly positioned piles.

All condemned or abandoned holes for piles shall be backfilled with lean concrete up to

the cut-off level.

13. BORED CAST-IN-PLACE PILES

13.1 Boring and Casing

The piles shall be bored up to the depth indicated by the piles drawing submitted by the Contractor and approved by FEWA/Engineer. For each pile, the Contractor will draw up the geotechnical profile of the boring with description of the strata and samples taken for each stratum as mentioned in the piling record item of these Specifications.

A representative sample (even disturbed) from each stratum will be kept in tight packing until the

end of the works.

All boring machines which disturb the surrounding soils and particularly those using suction process will be prohibited.

If any block of hard material or any part of existing foundations or piles is encountered during

boring, the surrounding soil shall be disturbed as little as possible during drilling through the block. The boring of a hole located closer than 3 diameters centre to centre of a pile shall be subject to

the explicit approval of FEWA/Engineer. The bottom of the hole shall be regularly checked during boring to detect any hazard (e.g.

unexpected change in soil condition, presence of erratic blocks,) to produce the geotechnical cross-section and control the stability of the bottom of the hole.

The use and type of the boring-chisel must be submitted for the approval of FEWA/Engineer. The casing shall be free from distortion and will be of uniform cross section throughout its length.

The base of the casing shall always be located below the bottom of the boring. During drilling, the thickness of water and soil within the tube must be large enough to create an over-pressure at the base of the drilling-tool.

Boreholes which are not concreted shall remain covered at all times.

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These piles shall have a minimum diameter of 600 mm and shall be formed by supporting the borehole with temporary casing throughout the length advancing a steel casing down to the required depth and by removing the soil and/or rock from inside the casing. The bottom of the casing shall be kept sufficiently far below the boring to prevent the inflow of soil and the formation of cavities in the surrounding ground.

Concrete for bored piles shall be self-compacting with a slump range of 150 – 180 mm. Concrete shall only be placed through a tremie pipe to ensure that the concrete is not segregated.

When concreting under water, an efficient technique with a water tight tremie and a hopper attached at its head by watertight connection shall be used. The tremie must always be kept full of concrete and penetrate well into the concrete with adequate safety against accidental withdrawal.

Concreting of piles shall be carried out as a single continuous operation, and concrete within

temporary casings shall never be vibrated. The concrete of the pile shall be brought up to at least 60mm above the cut off level to allow for complete removal of slush and of any foreign material from the main pile to obtain sound and uniform concrete.

Continuous-flight-augured bored piles (C.F.A) shall be used under special site conditions with the

approval of FEWA.

13.2 Anchorage in the Rock

When different top levels of rock are encountered during the pile boring, the anchorage levels will be adopted and submitted for the approval of FEWA/Engineer.

When the bedrock is reached, the steel casing has to be pushed as far as possible into it, in order

to avoid penetration of sediments by any possible space between the rock and the rim of the steel casing.

14. STEEL REINFORCEMENT

The piles shall be longitudinally reinforced for the whole length. The pile reinforcement drawings

for execution shall be submitted by the Contractor and approved by FEWA/Engineer. The length of longitudinal bars above cut-off level is based on the required length to be

embedded in the pile cap according to relevant Specifications and Drawings. Steel reinforcement used for cast in situ concrete piles shall consist of epoxy fusion coated high

yield steel with yield strength 460 N/mm2 in accordance with the requirements of BS 4449/4461 or the relevant ASTM Standard.

The concrete cover to reinforcement shall be 75 mm minimum.

Reinforcement cages must be sufficiently rigid, and the whole length of the pile shall be reinforced with longitudinal steel bars, area not less than 0.8% of gross area of section of pile. Steel links/hoops/spirals shall have at least 8mm diameter and a volume of not less than 0.2% of gross volume of the concrete pile. The minimum reinforcement for any pile shall be 6 bars of 20 mm diameter.

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Stirrups shall consist of hoops with a minimum diameter of 10 mm and a pitch of 150 mm.

Reinforcement cage:

The stirrups shall fit tightly to the longitudinal bars and be fixed to them by coated steel wires.

The inner diameter of the reinforcement cage shall be larger than 1.25 times the outer diameter of the tremie concreting tube.

Installation of the reinforcement

When the reinforcement cage of a pile consists of several sections, the assembling of these parts has to be made before or during insertion within the casing, taking into account the necessary overlapping between the sections.

The reinforcement cage shall be perfectly centered within the casing so that the cover, over all reinforcement including binding wire, is not less than 7.5 cm of concrete.

Before installation of the reinforcement cage, the Contractor shall check the complete cleaning of the bottom of the hole. All disturbed soil and debris must be removed from the hole.

If the check at the base of the pile shows a penetration of sediments between the rock and the end of the steel casing, the Contractor must submit for the approval of FEWA a method which ensures the sealing of the casing within the rock.

The reinforcement cage must remain stable during concreting and removal of the temporary casing. The handling of the cage during loading, unloading and installation within the holes has to be made with care in order to reduce the deformation and to avoid breaking the welding or the binding wires.

Splicing of longitudinal bars shall be made by mechanical couplers or any approved method.

15. CONCRETE

15.1 Composition

Concrete for piles shall be as per FEWA specification:

Concrete Class : C 40 Maximum Water/Cement Ratio : 0.35 Maximum size of aggregates : 20 mm

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3MIX PROPORTIONS / M

OPC / MSRPC 200 Kg.

GGBS 200 Kg

Microsilica 20 Kg.

20mm fully crushed All in

aggregate grading

10mm fully crushed

5mm washed sand

Dune sand

Super plasticizer 10 litre min.

Calcium Nitrate 5 litre min.

The correct mix design shall be studied and submitted by the Contractor to obtain the specified

workability, strength and durability. The minimum grade of the concrete for piles shall be 40 N/mm2.

Calcium Nitrite shall be added in accordance with section 8, CONCRETE AND

REINFORCEMENT. Unless otherwise mentioned elsewhere, the minimum content of cement shall be 420 kg/m3.

Concrete composition, production, transport and control testing shall be conform to relevant British Standards. The workability measured by standardized procedures should be adequate for the method of placing used. Note:

Mix design given are to be checked by the contractor for consistency of particular grades. Based on the given guideline, contractor to arrange trial mix test with concrete supplier before the execution of work. The proportions shown are not to be taken as final and the basic materials to be used shall not be changed. For getting maximum workability and slump specified for specialist concrete works, super plasticizer shall be used at site with the approval of FEWA/Engineer.

15.2 Concreting

Mixing of concrete shall be in accordance with section, CONCRETE AND REINFORCEMENT. The method of concreting into the pile shall ensure a continuous operation. The waiting times

between the concrete trucks may not exceed half an hour. No concreting interruption will be tolerated.

Before starting the concreting and inserting the steel cage, the bottom of the hole has to be

cleaned. All loose, disturbed or remolded soil will be removed from the base of the hole. Insertion of the steel cage and the start of concreting shall commence immediately after cleaning.

If the check at the base of the pile shows a penetration of sediments between the rock and the end of the steel casing, the Contractor must submit for the approval of the FEWA/Engineer a method, which ensures the sealing of the casing within the rock.

All concrete is to be pumped into the pile through a steel pipe. After the concrete has reached

the required level, the remaining hole shall be immediately filled by gravely sand.

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After concreting of each pile, the concreting volume will be checked in relation to the theoretical borehole volume; for this purpose, a concrete curve is drawn up for each pile, truck by truck. A complete curve is established from the measurements of concrete consumption every meter on the length of the pile for 1 pile in every 50 piles. The concrete- curves (truck by truck and meter by meter) have to be daily provided to FEWA and included in the piling record.

If the concrete consumption is not normal (under-volumes or more than 30% of over-volumes)

special procedures will be taken by the Contractor in agreement with FEWA. The borehole shall normally be cleaned at least 1 hour before concreting. The cleaning must be

performed using circulation of clean water (less than 1% sand), aspiration pumps and any mechanical devices.

The concreting pipe shall be clean and water-tight (also the joints between elements). The inner

diameter of the pipe shall be approved by FEWA. The length of the concreting pipe shall be at least equal to the length of the pile. Before

concreting, the pipe will reach the bottom of the hole and is then raised by 30 cm maximum. The starting (first concrete pouring) must be made preserving the concrete from pollution. After this operation, the pipe must never be located less than 1.5 meter below the level of workable concrete within the pipe.

At all times, a sufficient quantity of workable concrete shall be maintained within the pipe to

ensure that the pressure from it exceeds that of the ground water.

15.3 Concrete control

The minimum strength of the concrete shall be 40 N/mm2.For each group of 10 piles, 6 representative pairs of cubes shall be taken. 3 pairs of cubes shall be tested after 7 and 28 days respectively. Cubes shall be taken for durability test also.

The tests results shall comply with BS 5328 last edition or approved equivalent. All costs relative to these control tests are to be borne by the Contractor.

16. PILING RECORD

For each pile, a piling record, giving the main checked values during execution will be drawn up

and updated by the Contractor with all the work hazards and incidents. The record shall be submitted daily for the approval of FEWA as the work proceeds.

The record shall include for each pile details on :

Location, reference number (corresponding to the number fixed on the implantation drawing), type and diameter of the pile;

Date and hour of start and end of each operation drilling, reinforcement setting, concreting;

Level from which the pile is bored or driven (platform level);

Level at the pile base;

Top level of the concreted pile before the cut-off operation;

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Useful length;

Used materials (driving or drilling tools, concreting equipment);

Condition at the bottom of the hole before putting down the reinforcement cage and before concreting;

Nature and description of the bored soils;

Poured concrete volume and theoretical volume (measured concrete curves);

Behaviour, workability, fluidity of concrete, results of the compression tests;

Water level within the hole before concreting;

Type of boring-chisel, lengths of piles where chisel has been used.

Records shall be submitted in duplicate to FEWA/Engineer every following working day.

The Contractor will submit for the approval of FEWA/Engineer a proposal of piling record sheets including all the details mentioned here above.

17. PILE TESTING (TYPE TESTS)

17.1 General

Before installation of working piles, the Contractor shall install two test piles of each pile type, solely for testing purposes and in order to check the pile design. Test piles shall be identical to the working piles and shall be constructed with the same equipment intended for all piles. Test piles shall be tested with a load of 250% of the proposed working load. Pile testing is to be done as per BS 8004 or other the relevant standards.

An acceptable test pile shall not fail under the test load, and the total settlement (after 24 hours)

under full test load (250% of working load) shall not exceed 7mm. In case test results are unacceptable, the Contractor shall either reduce the working load or change the pile system and the Contractor shall carry out additional test piles for the modified working load or system of piles.

Verify and confirm the initial recommendation values for the working load capacities stated in the

Soil Investigation Report and adopted for each diameter of piles proposed for use by carrying out a high strain dynamic load testing conforming to the ASTM 04945-89 standards on pilot and non working piles.

If results of tests on preliminary piles do not meet stipulated criteria, submit to the FEWA

proposals for revisions to piles, either in diameter or length, or both. The Contractor is to carry out, at his own costs, load tests, as deemed necessary and as directed by the FEWA, on further preliminary piles to revised design, and repeat revision, if necessary, until acceptable test results are obtained.

The Contractor may not commence any working piles before ensuring that satisfactory results are obtained from all specified preliminary test piles to the satisfaction of the FEWA.

The remainder of the piles constructed prior to the working failed pile test shall stand condemned

as unsatisfactory until demonstrated by the Contractor that the quality and bearing capacity of each individual pile on the site is acceptable.

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If result of tests on working piles do not meet stipulated criteria, the FEWA may order that additional piles be installed and that pile caps be redesigned to accommodate additional piles.

All costs incurred in the testing of piles, revision to piles and pile caps, and other parts of the

works affected, including Engineering and redesign costs, shall be paid by the Contractor, whatever the outcome of the tests, in accordance with the provisions of the contract documents.

17.2 Proof Load (Routine) Test

The Contractor shall carry out proof load tests on working piles for each type of pile with a

minimum of three proof tests. The maximum test load shall be 150% of the working load. Proof tested piles shall not fail and the settlement after 24 hours from the application of the test load (150% of the working load) shall not exceed 5mm.

17.3 Static Load Test

The Contractor will execute static loading tests on 1% of the total quantity of the piles or a minimum of 2 piles, whichever is the greater, at working pile load test.

The pile(s) to be tested will be indicated by FEWA/Engineer. The procedure to be followed is provided by ASTM D 1143 or by BS 8004 article 7.5.5.

Any other standard can be used as reference, provided that it is submitted for FEWA/Engineer 's approval.

The maximum test load is equal to 1.5 QN, where QN is the net vertical design load on the working pile.

Carry out a static load test to twice the designed load on at least two preliminary, non-working pile of each diameter to be used on the project, but not less than a total of two piles.

Unless other instructions are provided by FEWA/Engineer, the test is to be carried out not less

than 4 weeks after concreting of the pile.

The loading materials and equipment, the measurement devices and procedures have to be submitted for FEWA/Engineer 's approval by the Contractor.

All tests will be carried out only under the direction of an experienced and qualified supervisor

familiar with the test equipment and test procedure. All personnel operating the test equipment will have to be trained in that field. If tests provide unsuccessful results, the Contractor shall propose all necessary adaptation to the foundations. These proposals shall be submitted to FEWA/Engineer. Further pile tests shall be carried out as directed by FEWA/Engineer. All costs requested to perform the foundation adaptation and repeated pile tests shall be at the Contractor's expense.

Moreover, if any working piles fail under test, it shall be replaced at the Contractor's expense by

a pile or piles as indicated by FEWA/Engineer. The maximum settlement for the pile due to the test load shall be 8 mm.

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Confirm the uplift of each diameter of pile proposed for use on this project, by carrying out a static load test to 1.05 times the ultimate uplift load on at least one preliminary non-working pile of each diameter to be used on the project, but not less than a total of two piles. Piles used for down-wards load tests may also be used for tension load tests.

17.4 Pile Integrity Test

The Contractor shall allow for carrying out a low-strain integrity testing for all cast-in-place piles in accordance with the ASTM D 5882-96 standards to insure the sound construction of each pile. The type and method of testing employed is to be submitted for the approval of the FEWA/Engineer prior to commencement of testing. Further detail of the test is attached to the Soil Investigation Report.

All piles shall be tested by sonic integrity test to check any discontinuity in the pile such as

necking, enlargement or cracks, etc. On cast in situ piles the test shall not be performed earlier than 7 days after concreting. The method is to be submitted for FEWA/Engineer 's approval.

17.5 Dynamic Testing

At least three piles for each diameter shall be subject to dynamic testing to achieve twice the

design load. Piles to be tested are as indicated on the drawings and/or as directed by the FEWA/Engineer. Selected piles shall represent the main platform levels and possibly test smaller penetration of piles. The non-working and pilot piles shall establish also the ultimate capacity of piles, the working pile soil load transfer relationship (end bearing and skin friction).

The Contractor shall carry out high strain dynamic load testing to one and a half the design load

on two percent of the working piles in the project as designated by the FEWA/Engineer. Working piles may not be used as tension piles in a pile test. 17.6 Guidelines for Testing

The test load shall be applied by jacking against a Keatledge, ground anchors or reaction piles. The distance of the reaction piles shall not be less than three times the diameter of the test pile. The total capacity of the jacking system should be 20% greater than the test load.

The test shall be applied in the following increment to working load: 25%, 50%, 75%, 100%, 125%, 150%, 175% and 200%.

The load after each increment shall be maintained until the rate of movement is reduced to

0.25mm/hour. The working load shall be maintained for 12 hours. The test load shall be maintained for 48 hours. Reduce the load in increment equal to the loading increments. The loads shall be maintained

until the rate of recovery is reduced to less than 0.25mm/hour.

The total movement shall be recorded as follows:

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- On reaching the load test - At 15 minute intervals for one hour - At 30 minute interval from one hour upto 4 hours - At one hour interval after 4 hours

The total movement of the pile under the full load test and its recovery shall be within the limits. Within 24 hours of completion, the test results shall be submitted to FEWA/Engineer in the form

of a tabulated site readings plus the following plotted data:

- Load and settlement plotted above and below a common base line of time. - Settlement and recovery plotted vertically against the base line of time.

The settlement shall be recorded by an dial gauges able to record 0.25 mm accuracy registering against a datum beam by means of an optical level.

A pile shall be considered to have failed the test when any of the following conditions apply.

- On completion of the test, the residue settlement after the test load is removed exceeds 6mm or 10% the pile diameter, whichever is lesser.

- The test load as specified in the contract could not be achieved, or that it continues to settle under test load conditions with a settlement larger than 0.005mm per ton of the total Load per hour.

- The integrity test showed that the pile to be poorly formed, necked and in the opinion of the FEWA would compromise the piles safe load carrying capacity and durability

17.7 Tolerances

All survey works utilizing coordinates system based on the ACD bench marks and the settling out of main grid lines shall be carried out by the Contractor. The tolerances are as follows:

The installation of marker pins at pile positions as required by the FEWA shall be accurate to 20mm in any direction

The maximum permitted deviation of the finished pile position shall be 50mm in any direction from the designed position.

Variation in diameter : -25mm

Maximum deviation from plumb; 2% Any additional costs involved in enlarging or strengthening pile caps and/or providing additional piles in consequence of exceeding the above deviations, will be borne by the Contractor.

18. PREPRODUCTION PILES

The Contractor will execute quality tests on a preproduction pile at each Site where piling is required.

These piles are carried out according to the same Specifications used for all the other piles

belonging to the project at the beginning of the piling works. However, in this particular case, the test load is equal to 2 QN, Where QN is the net vertical design load of the tested pile. Except for

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this test load, the procedure applied for the test will be the same as the general procedure explained in the paragraph Static Loading Tests.

These preproduction piles will not be used as foundations for the buildings. The piling works shall not be started until approval of the quality test results by FEWA. The location of the preproduction piles, depending on the results of the soil investigations, has

to be proposed to FEWA and submitted for FEWA's approval.

19. DRIVEN PILES

Pre-cast concrete piles shall be square or rectangular shaped in cross section with beveled edges. Forms shall be tight and rigid. Piles shall be marked with casting date and shall be cured for 28 calendar days.

The Contractor shall drive enough test piles to determine the length of pile required to secure

the specified bearing and to determine required penetration in the various areas of the work. These tests shall be made sufficiently in advance of the pile driving to prevent delay in the progress of work and so that the Contractor will have on hand, at all times, piles of proper length to meet any conditions that may arise.

The pile driving formula shall be used to give the relation between the measured permanent

displacement (or set) of the pile at each blow of the hammer to the ultimate bearing capacity of the pile. After performing the pile load test a correcting coefficient shall be applied to the formula in order to be of reasonable reliability for the site.

Hiley’s formula shall be used for pile driving. However, the Contractor may propose other

driving formula subject to the approval of FEWA/Engineer. The final of a pile set shall be recorded either as the penetration in millimeter per 10 blows or as the number of blows required to produce penetration of 25mm.

20. PILE FOUNDATION DESIGN

a) The general design of piles shall be in accordance with the British Standard Code of Practice for Foundations BS 8004 and BS 8110. The Contractor must submit sheet calculations for approval, at least two weeks prior to the commencement of piling works.

b) the Contractor shall be responsible for the adequacy of the pile foundations installed to

carry the design downward loads or upward loads specified on the Drawings, and if necessary, in addition allowance shall be made for the down-drag or uplift loads.

c) Piles shall be designed to carry all compression and lateral loads in the concrete on the

effective cross sectional area of the pile. In the case of piles required to act in tension or bending, the stresses in the reinforcement shall be in accordance of BS 8110.

d) The Ultimate bearing capacity of a pile shall be taken as defined in the BS 8004. The

factor of safety shall be taken as the ratio of the ultimate bearing capacity to the design load and shall be not less than 3.

e) The Contractor shall submit to FEWA/Engineer the following:

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- Full method statement - Proposed length of piles - Reinforcement details - Design calculations

The above includes submitting along with the Geotechnical Specialist's certificate, pile locations, diameters, toe and cult-off levels etc., and any other details which may deviate from those shown in the tender documents and which formed the basis of this tender.

f) The arrangement shown on the drawings is based upon end bearing pressures working

load capacities given in the soils report. It results in pile caps suitable to the architectural layout and the basement and underfloor services. The Contractor shall be responsible for the actual design of the total and individual pile foundation system.

g) FEWA/Engineer shall not be held responsible for the values given in the soils report,

while the Contractor shall be responsible for correctly interpreting the report in the respect of Pile Design and construction, in case FEWA/Engineer gives soil report. Where the Contractor considers the report to be insufficient for his purpose, then he should allow in his tender sum for any additional site investigation and testing that he considers necessary to carry out the pile design and construction.

h) If pile diameters or layout are changed from those shown on the Drawings, the contractor

shall be responsible for all costs involved due to re-design of changes to pile caps or other work affected. The contractor shall also be responsible for obtaining all approvals and No Objection Certificates required by the Municipality or any other concerned Authorities.

i) The pile diameter shall be taken to mean the outside diameter of the permanent or

temporary casing or the outside diameter of the excavating tool. Where a pile is cased for part of its length, the least diameter shall be taken as the pile diameter.

21. SUBMITTALS

Submit layout and detail drawings for piles. Show sizes, cut-off elevations, anticipated base elevations, platforms, reinforcement and applied design loads.

22. SAFETY

Comply with the requirements of BS 5573.

23. SETTING OUT

The Contractor will be responsible for setting out the grid lines and column centers, and establishing the datum levels.

The Contractor will be responsible for setting out the piles in relation, and the cut-off level of the

piles from the datum levels.

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24. EXECUTION

a) Piles shall be formed in such manner or sequence as to ensure that no damage is sustained by previously formed piles. For piles cast in dry bores using temporary casing and without the use of a permanent lining, pile heads shall be cast to a level above the specified cut-off level so that after trimming a sound concrete connection with the pile can be made. The casting level shall be within tolerance above the cut off level but shall not be above the commencing surface level.

b) No pile shall be cast with its head below standing water level unless approved measures are

taken to prevent the inflow of water causing segregation of the concrete as the temporary casing is extracted, and where applicable, the standing water level for each pile shall be agreed with FEWA/Engineer, and this level is to be treated as the cut-off level for the purpose of calculating the tolerance.

c) Provide rigid guide casing 3.0m long for locating the pile center and to ensure that maximum

deviation at cut-off elevation from position on plan is not exceeded. Where soil condition is weak and collapse of pile shaft is anticipated, longer casing may be used as instructed by FEWA/Engineer.

d) The plumb of the bored hole is checked on the Kelly of the drilling rig while advancing the

borehole. Vertically of the Kelly is controlled by spirit level and corrected when required during the course of drilling.

e) When bentonite slurry is used to support the uncased borehole, the head shall be maintained

upto working platform at all times while boring.

f) Upon reaching the final elevations, the bentonite slurry shall be circulated for a period as required, to remove the soil cuttings from within the borehole, the return slurry from the borehole shall be regularly checked to determine that the bearing stratum is cleaned out prior to concrete placement When approved by the FEWA, provide equipment and material to permit concrete to be placed by Tremie method.

g) Under any circumstances, no bored pile shall be left not cast with concrete for more than 3 hours. Pending the preliminary test results, FEWA/Engineer may direct the last meter of the pile shall be bored just before concrete arrives to the site.

h) For Tremie concreting, submit description of method proposed in writing and obtain written

approval of FEWA/Engineer in advance of starting work on concreting piles.

i) Install reinforcing cage. Provide spacers to ensure minimum concrete cover of 75mm.

j) Transfer concrete from mixer to pile position without segregation and place in pile, by a method which will avoid contamination, within a maximum of two hours of dispatch from plant.

k) Fill concrete sufficiently in one continuous operation to ensure that sound uncontaminated

concrete has been cast upto specified cut off elevation.

l) Piles shall be terminated in faultless concrete at cut-off level indicated on the drawings.

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m) Contractor shall be responsible for any additional cost in cutting down or making up piles to this elevation, or for replacing defective concrete upto cut-off level.

25. BENTONITE

Where it is proposed to use bentonite slurry in the installation of piles, he shall include for all expenses in supplying, mixing, testing, draining of bentonite from spoil, replacement of all contaminated bentonite and disposal from site. This bentonite is to be regularly checked for density, viscosity, shear strength, and pH value, and these values should fall wall within the following limits. a) Density at +20 degrees Celsius : 1.01 to 1.10 g/ml b) Viscosity at +20 degrees Celsius : 30 to 90 seconds (marsh cone). c) Shear strength at +20 degrees Celsius

(Shearometer) : 1.4 to 10.0 N/square me.

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