specification bored piles

ADNOC NEW MEDICAL CENTER Package 1: Enabling Works Volume 4: Specifications Project No. 7011- Agreement No. 147011C1

Section 316300 – Bored Piles of 24

SECTION 316300 – BORED PILES

PART 1 - GENERAL

1.1 SUMMARY

A. Install 750-millimeter diameter bored piles into strata at the locations and lengths shown in the contract drawings.

B. The Work of this Section includes, but is not limited to: excavation; caliper log-ging; concrete placement; transportation and disposal of excavated materials off site; supply, circulation, maintenance, and disposal of polymer drilling fluid; re-moval of concrete overpour or other irregularities which interfere with other struc-tural elements; furnishing and installing equipment for crosshole sonic logging (CSL); and preparation of concrete surface at the top of piles for impulse re-sponse spectrum (IRS) testing. The piles are to be designed by the Contractor.

C. Provide two static axial tension load tests of bored piles.

D. Production piles shall be installed by the same means and methods used during installation of successful load test piles and as accepted by the Engineer.

1.2 REFERENCES

A. Standards:

1. ASTM D1143 Standard Test Method for Piles under Static Axial Com-pression.

2. ASTM D3689 Standard Test Methods for Deep Foundations under Static Axial Tensile Load.

3. ASTM D5753 Standard Guide for Planning and Conducting Borehole Geophysical Logging

4. ASTM D5882 Standard Test Method for Low Strain Integrity Testing of Piles

5. ASTM D6167 Standard Guide for Conducting Borehole Geophysical Logging: Mechanical Caliper

6. ASTM D6760, Integrity Testing of Concrete Deep Foundations by Ultra-sonic Crosshole Testing.

7. Standard Specification for the Construction of Drilled Piers (ACI 336.1) by The American Concrete Institute (latest edition).

8. ADSC Standards and Specifications for the Foundation Drilling Industry with latest revision dated 1999.

9. ACI 301 – Standard Specifications for Structural Concrete.



10. ACI 318 – Building Code Requirements for Structural Concrete.

B. Other References

1. Building Research Establishments Special Digest (2005) – Concrete in Aggressive Ground.

2. Construction Industry Research and Information Association.

a. Report PG7 – Pile load testing procedures. b. Report C144 – Integrity Testing in Piling Practice.

3. American Petroleum Institute, API 5L – Specification for line pipe. 4. Construction Industry Research and Information Association:

a. Report PG7 – Pile load testing procedures. b. Report C144 – Integrity Testing in Piling Practice.

5. American Petroleum Institute, API 13A Specifications for drilling fluids Materials 17th

The Standards referred to in this Specification, together with any other references specified shall be the latest editions including all current amendments and additions. Any differences between their requirements and this Specification shall be submitted to the Engineer for his ruling.

Edition.

C. Geotechnical Investigation

Geotechnical investigations have already been carried out; copies of geotechnical investigation report are available with the Employer or the Engineer. The Contractor shall note that all the above information has been given for information only and no claim from the Contractor will be entertained for any accuracy or discrepancy in the same.

The Contractor is to satisfy himself that the soils data contain sufficient information for the execution of all work.

1.3 SUBMITTALS

A. Piling Method and Program

1. The Contractor shall submit a comprehensive Method Statement for the installation of the piles and the performance of the static load tests for review and approval by the Engineer. The Method Statement shall include: the QA/QC system to be used; all relevant construction means and methods details, and the plant he proposes to use. Any additional and/or alternative construction means and methods to that specified shall be subject to review and approval by the Engineer; any required additional testing shall be at the Contractor’s expense. The load test plan shall include, at a minimum, method and schedule, loading frame,



configuration, size and types of weights, reaction frames and details of cribbing or reaction piles (as appropriate), load cell calibration/verification certificates at least 2 weeks prior to start of load tests. Only calibrations done not more than 1 month prior to the start of the load tests shall be accepted.

2. Submitted information shall include, at a minimum: proposed equipment, methods, and sequence of operations to be used to excavate and maintain the excavation; method of monitoring verticality of the excavation during drilling; method of providing and checking the cleanliness of the excavation bottom; method of performing caliper logging of the excavation; methods to produce, maintain, mix, monitor, and reclaim polymer slurry drilling fluid; method of steel reinforcing cage placement and securing; method of tremie concrete placement; and method for backfilling excavations above the specified cutoff elevations after concrete placement. Submit data for the synthetic polymer slurry giving the recommended physical and chemical properties of the slurry, and proper use and maintenance of the polymer slurry.

3. Submit qualifications of the piling Contractor. The submittal shall include resumes of the project manager, superintendent, and field foreman in charge of the Work and details of similar previous projects. Minimum personnel qualifications shall include a minimum of five years experience on projects installing piles of the same diameters to similar depths in rock using polymer slurry drilling fluid methods. Minimum previous project experience shall include five projects with a similar number of piles of the same diameters installed to similar depths in rock using polymer slurry drilling fluid methods.

4. Submit criteria used for evaluation of Crosshole Sonic Logging (CSL) results and impulse response spectrum (IRS) testing results for approval by the Engineer.

5. Should re-grouting of the pile shaft be proposed, the purpose and means and methods must be thoroughly described. All quality control methods to ensure the post-grouting has achieved the desired result must be outlined to the satisfaction of the Engineer and the design team.

6. The Contractor shall submit to the Engineer the proposed sequence of boring and excavation, having regard to the avoidance of damage to adjacent piles.

7. The Contractor shall inform the Engineer of the intended work program and schedule for the following day and shall give minimum 72hours notice of his intention to work outside normal hours and Public Holidays.

8. The Contractor shall submit within 7 calendar days after the award of contract for approval a detailed construction program in the form of a work plan and schedule. When agreed, the work plan and schedule shall be considered the Construction Program and used by the Contractor for his detailed control of the works and for monitoring construction progress.

B. Piling Method and Program



1. The Contractor shall keep records as follows for the installation of each pile and shall submit two copies of these records to the Engineer not later than noon of the next working day after the pile was installed. The signed records will form a record of the work.

2. Any unexpected conditions shall be noted in the records. 3. The form of record shall be approved by the Engineer.

C. Data to be recorded.

1. Pile reference number (location). 2. Pile type. 3. Drilling slurry (if used) to stabilize element excavation (including mineral

types, polymers, and any additives used to modify the slurry prior to element cleaning and concreting.

4. Drilling slurry properties (sand content, density, pH, viscosity) during drilling and prior to element reinforcing steel placement and concreting.

5. Results of element bottom cleaning (including measured bottom sediment thickness prior to reinforcing steel placement and concreting.

6. Nominal cross-sectional dimensions of pile. 7. Nominal element dimensions of the socket within the bearing stratum. 8. Standing groundwater level from direct observation and given site

investigation data. 9. Data and time of pile excavation. 10. Date and time of reinforcing installation. 11. Date and time of concreting. 12. Ground level expressed in terms of local municipal datum at works

position at commencement of installation of pile (commencing surface). 13. Working level expressed in terms of local datum on which piling base

machine stands. 14. Depth from ground level at pile position to pile toe. 15. Toe level expressed in terms of local datum. 16. Pile Cut-off level expressed in terms of local datum. 17. Length of temporary casing(s). 18. Length of permanent casing (if any). 19. Length and details of reinforcement. 20. Concrete mix. 21. Volume of concrete supplied to pile and ratio of actual volume to

theoretical volumes. Provide incremental volumes and ratios at maximum 2 meter intervals during entire concreting operation.

22. All information regarding obstruction delays and other interruptions to the sequence of work.

23. The as-built coordinates of each pile installed. 24. Details of tremie pipe used to place concrete. 25. Details of plant used to form pile including plant reference number. 26. Verticality of element excavation. The shaft shall be vertical to the full

depth of the pile.



27. Confirmation of the pile shape by mechanical caliper logging or Koden sonic logging prior to concreting.

28. Confirmation of the post-construction integrity of the pile using cross-hole sonic logging (CLS) and low strain pile integrity testing (PIT).

29. Concrete records, slump, plot of actual versus theoretical volumes per pile.

The Contractor shall report to the Engineer the details of any piles that are installed out of tolerance no later than noon of the next working day and shall obtain the Engineer’s approval for any remedial work that is required.

D. Concrete Mix Design: Submit concrete mix designs at least 30 days before placing concrete.

1. Mix designs shall be prepared or reviewed by an approved independent testing laboratory retained by the Contractor in accordance with requirements of ACI 301 and ACI 318, signed by a registered design professional licensed to practice where the project is located, and shall be coordinated with design requirements and Contract Documents. Data shall be from the same production facility that will be used for this Project.

2. Mix Design data shall include but not be limited to the following.

a. Design Compressive Strength: As indicated on the Drawings. b. Proportions: ACI 301 and ACI 318. c. Gradation and quality of each type of ingredient including fresh

(wet) unit weight, aggregates sieve analysis. d. Water/cement material ratio. e. Evaluate and classify fly ash in accordance with ASTM D 5759. f. Report chemical analysis of fly ash in accordance with ASTM C

311. g. Classify blast furnace slag in accordance with ASTM C 989. h. Slump: ASTM C 143. i. Certification and test results of the total water soluble chloride ion

content of the design mix - AASHTO T260 or ASTM C 1218. j. Air content of freshly mixed concrete by the pressure method,

ASTM C 231, or the volumetric method, ASTM C 173. k. Unit Weight of Concrete: ASTM C 138. l. Design strength at 28 days, as indicated on contract documents:

ASTM C 39.

1.) Document strength based on basis of previous field expe-rience or trial mixtures per ACI 301. Proportioning by Wa-ter-Cement Ratio is not permitted.

2.) Submit strength test records, mix design materials, condi-tions, and proportions for concrete used for record of tests, standard deviation calculation, and determination of re-



quired average compressive strength. 3.) If early concrete strengths are required, contractor shall

submit trial mixture results as required. m. Test records to support proposed mixtures shall be no more than

12 months old and use current cement and aggregate sources. Test records to establish standard deviation may be older if necessary to have the required number of samples.

n. Manufacturer's product data for each type of admixture. o. Manufacturer’s certifications that all admixtures used are

compatible with each other. p. Certification from a qualified testing agency indicating absence of

deleterious expansion of concrete due to alkali aggregate reactivity in accordance with ASTM C 33.

1.4 QUALITY ASSURANCE

The contractor shall operate a quality system approved by the Engineer for all stages of work.

A. The Contractor will keep a bored pile log, including items completed each day, job and weather conditions, soil and rock strata encountered, water conditions, drilling difficulties, obstructions, casing size and location, slurry type, bottom cleanout and slurry removal, description of bearing material, depth and size of shaft, the shaft, reinforcement placement, concreting, and any other pertinent construction details.

B. Upon completion all pile installation the Contractor shall submit to the design team pile installation reports for review.

1.5 QUALITY ASSURANCE BY ENGINEER

A. The Engineer will be on the site during pile installations to observe if piles are installed in accordance with design and construction requirements specified herein.

B. The Engineer will submit full data to the design team for review to facilitate the corrective design requirements. The Engineer will certify that the piles, as installed in the corrective methods, comply with the Design and Code requirements.

C. The Engineer will observe the installation of the each pile shaft and will determine when the shaft has reached the required depth.

D. No pile installation work shall be performed without the presence of the Engineer. The Contractor shall notify the Engineer a minimum of 72 hours prior to start of drilled pile installation and load test work.



E. The Contractor shall cooperate with the Engineer to facilitate the progress of his inspection work. If the Contractor fails to cooperate with the Engineer, the Engineer shall have the right to suspend work until the problem is rectified.

1.6 QUALITY ASSURANCE BY TESTING AGENCY (CONCRETE) AND OTHER TESTING (CSL, PIT)

A. The Contractor shall retain the services of an independent testing agency to per-form concrete quality assurance testing and post-integrity testing of piles.

B. Coordination with Testing Agency: The Contractor shall have sole responsibility for coordinating their work with the testing agency to assure that all test and in-spection procedures required by the Contract Documents and Public Agencies are provided. The Contractor shall cooperate fully with the Testing Agency in the performance of their work.

C. Duties of the Testing Agency:

1. Reports: The Testing Agency shall prepare daily reports of the concrete work including progress and description/area of work, tests made and results. The daily reports shall be collected and delivered to the Engineer and the Employer.

2. Rejection: The Testing Agency has the right to reject any material, at any time, when the material or workmanship does not conform to the Contract Documents. The Testing Agency shall report deficiencies to Engineer, Employer, and Contractor immediately.

D. Source Quality Control

1. The Testing Agency shall conduct concrete quality evaluations for compliance with Specifications as follows;

a. Review and test Contractor's proposed materials. b. Review and test Contractor's proposed concrete mix designs. c. Secure and test production samples at plants or stockpiles. d. Check batching and mixing operations to extent deemed

necessary to assure compliance with Specifications.

E. Field Quality Assurance.

1. General: The Testing Agency shall test and inspect concrete materials and operations as Work progresses. Failure to detect any defective work or material shall not in any way prevent later rejection when such defects are discovered nor shall it obligate the Engineer for final acceptance.



2. Testing Agency is responsible for monitoring concrete placement. The Testing Agency shall provide qualified personnel at site to monitor concreting operations as follows:

a. Record temperature of concrete at time of placement. b. Record weather conditions at time of placement, including

temperature, wind speed, relative humidity, and precipitation. c. Record types and amounts of admixtures added to concrete

batches, including that added after departure of concrete trucks from batch plant.

d. Record amounts of and monitor dosing of high-range water-reducing admixtures added at site for site-added admixtures and redosing for plant-added admixtures.

e. Monitor consistency and uniformity of concrete. f. Monitor preparation for concreting operations, placement of

concrete, for conformance with Specifications.

3. Testing Agency shall conduct tests of concrete as follows:

a. Testing frequency: Two sample sets for all tests listed below shall be taken at each bored pile. Each set shall have 7-cylinders.

b. Obtain each test sample from different batches selected on a strictly random basis before commencement of concrete placement. Record location in structure of sampled concrete.

c. Determine air content of normal weight concrete in accordance with either ASTM C 231 or ASTM C 138, or equivalent IS.

d. Determine unit weight of normal weight concrete in accordance with ASTM C 138, or equivalent IS.

e. Conduct slump tests in accordance with ASTM C 143, or equivalent IS.

f. Conduct strength tests of concrete as follows.

1.) Secure sample sets in accordance with ASTM C 172, or equivalent IS.

2.) Mold cylinders in accordance with ASTM C 31 (or equiva-lent IS) and cure under standard moisture and temperature conditions in accordance with ASTM C 31, Section 7 (a) (or equivalent IS).

3.) Test cylinders in accordance with ASTM C 39 (or equiva-lent IS).

4.) For 28 day mixes mold six cylinders. Test one cylinder at seven days, and three cylinders at 28 days. The 28 day strength shall be the average of the three28 day cylinders. Two cylinders shall be retained in reserve for later testing if required.

5.) If one cylinder in a test manifests evidence of improper



sampling, molding or other damage, discard cylinder and base test results on that of remaining cylinder.

4. Testing Agency shall evaluate concrete for conformance with Specifica-tions as follows.

a. Slump: Testing Agency shall maintain a slump moving average, comprised of the average of all batches or most recent five batches tested, whichever is fewer.

b. Strength test:

1.) Testing Agency shall maintain a compressive strength moving average, comprised of three consecutive strength test results, for each mix design used in Work.

2.) Strength level of concrete will be considered satisfactory provided averages of all sets of three consecutive strength test results (i.e. moving average) equal or exceed specified 28-day strength, and no individual strength test result falls below specified 28-day strength by more than 3.5 MPa.

3.) If strength tests fail to meet minimum requirements at 28 days (or longer for the reserve cylinders, concrete represented by such tests shall be considered questiona-ble. The Engineer may require the Contractor perform a core drill of the full depth of the pile for quality examination and strength testing of core specimens.

1.7 TENDER SUBMITTALS

A. The Contractor shall, when tendering, supply full details of:

1. The method and plant to be used in forming the specified pile type. 2. The standards of control to be used. 3. The construction sequence. 4. The method statement. 5. Concrete mix design, including slump loss data, and details regarding

what (if any) additives may be added to the mix in the field to improve workability while not to adversely impacting the design concrete strength and performance.

6. Any confirmation tests proposed for the site.

1.8 SITE CONDITIONS

A. Prior to commencing work, records of drains, cables, mains and other services shall be obtained and made by the Contractor to ensure that his Works will not cause damage to these services.



PART 2 - PRODUCTS

2.1 MATERIALS

A. Concrete Mix 1. Please refer to Section 033030 Cast-in-Place Concrete.

B. Reinforcing Steel

1. The reinforcing steel shall be furnished and installed as shown as shown on the approved shop drawings. It shall be accurately placed to obtain the thickness of concrete cover shown.

2. Steel reinforcement shall have a yield stress and concrete cover as speci-fied on the Structural Drawings.

3. Steel cages shall have pre-approved spacers to maintain the cages cen-tered within the shaft. The spacers shall be located at the tip and the top of the cages, with additional spacers located not more than 5-m on-center for the full embedded length of the shaft. The spacers shall be attached so as to prevent bending prior to placement in the shaft, and shall be ap-proved by the Engineer prior to use. The size of the spacers shall be such that a minimum 75-mm concrete cover inside the shaft is main-tained.

4. Steel cages shall be properly and securely fabricated such that the steel bars and ties maintain their designed locations and configurations. Rein-forcement in the form of a cage shall be assembled with additional sup-port necessary to form a cage, which must be lifted and placed without permanent distortion. Inner support links shall not be placed within 750 mm of the pile cut-off level. Intersection bars shall be fixed together by approved means. Hoops, links or helical reinforcement shall fit closely around the main longitudinal bars and be bound to them by approved wire, the ends of which shall be turned into the interior of the pile. Alter-nate method of cage fabrication will be considered. Reinforcement shall be placed and maintained in position to provide the specification projec-tion of reinforcement above the final cut-off level.

5. Clip on spacers will not be considered acceptable on their own. The spacer (approved by the Engineer) is to be tied to the main bar using ei-ther pre-approved tie wire or zip ties.

6. Where concrete spacers are to be used, the Contractor is to provide test results demonstrating that the spacer is formed from equivalent strength concrete as is to be used for the pile construction.

7. The number of laps in longitudinal steel bars shall be kept to a minimum. Joints in reinforcement shall be such that the full strength of the smaller of the bars being lapped is effective across the joint and shall be made so that there is no detrimental displacement of the reinforcement during the construction of the pile. All splices shall be staggered so they do not oc-cur at the same level within the pile.



8. Mechanical Tension Splices for Reinforcing Bars shall meet or exceed performance requirements of specified reinforcement and shall be ap-proved by the Engineer.

9. Reinforcement cages shall be placed under their own weight and not by the application of force. The means of inserting the reinforcement cages shall not cause bucking or lateral displacement of the cages, and shall be to the approval of the Engineer.

10. Welded joints and joint welding procedures shall be in accordance with BS EN1011, or equivalent IS. Any structural welds are to be undertaken by person carrying current, accredited welders’ certificates only.

C. Steel Casing

Temporary steel casings shall conform to the shape of the piles, of the dimensions indicated on the Drawings and shall be of sufficient strength to maintain shape and location during boring and placement of concrete. The casings shall be sufficiently watertight to exclude ground water during placing of concrete.

D. Drilling Fluid

1. Water is an acceptable drilling fluid provided a stable hole is maintained. 2. Bentonite slurry shall not be used as drilling fluid. 3. Polymer slurry drilling fluid, if used, shall be a stable suspension of poly-

mer in potable water. The Contractor shall anticipate encountering brack-ish groundwater. The Contractor shall modify the slurry mix as required so as to maintain a stable suspension at all time. a. The density of the polymer slurry shall be such that adequate ex-

cavation support and groundwater control is provided and that the slurry will be readily displaced by the tremie concrete. Additives shall be used in the slurry if needed to maintain the necessary properties for installation of the pile, as specified, and in accor-dance with the recommendations of the slurry manufacturer.

4. Drilling fluid loss in the open excavation shall be limited to a drop in the slurry level of no greater than 25 mm per hour per the total length of ex-cavation, and no more than 600 mm total in a 24 hour period.

5. Slurry properties shall be maintained as specified in Section 3.3 of this Specification.

2.2 EQUIPMENT

A. Provide equipment, machinery, tools, and other apparatus for drilling, digging, pumping, and hauling. Provide ample standby equipment to prevent distortion or caving so that work may be carried on without interruption.

B. Provide hoisting equipment of sufficient capacity to handle casing, reinforcing



cages, sleeves, and other materials.

C. The equipment shall be clearly marked at all times at locations specified by the Engineer in meter increments, such that the Engineer can easily infer the shaft tip depth or elevation. Alternatively, the Contractor shall provide a digital display providing the approximate drill depth.

2.3 TOLERANCES

A. Setting out of the main grid lines shall be carried out by the Contractor. The in-stallation of piles at positions as required by the Engineer shall be accurate to 75 mm as measure at cut-off level, in any direction. This tolerance shall ensure that pile heads are cast to a level above the specified cut-off so that, after trimming, a sound concrete connection with the pile can be made in accordance with the specified strength and durability characteristics.

B. At the commencement of installation, the equipment governing the alignment of the bored pile shall be made vertical for the entire depth of the pile.

C. Forcible corrections to concrete piles to overcome errors of position or alignment shall not be made.

PART 3 - EXECUTION

3.1 PRE-CONSTRUCTION MEETING

A pre-construction meeting will be held prior to the Contractor mobilizing his equipment to the site. At the meeting, the Contractor’s proposed means and methods for installing the test drilled shaft and performing the load tests specified herein, will be discussed and finalized. The Contractor shall perform the test drilled shaft installation and load test work in accordance with these specifications and any modifications agreed to at the pre-construction meeting. The Contractor shall be solely responsible for the adequacy of all operations.

3.2 WORKING PLATFORM

A. Piles may be constructed from a working platform above foundation level.

B. If the piles are constructed from a working platform above foundation level and a temporary casing is used to support the sand material, the temporary casing may not be extracted until the pile concrete has set to prevent collapse of soil into the fresh concrete.

C. If piles are constructed from a working platform above foundation level, excava-tions shall not be backfilled until the pile concrete has set to prevent contamina-



tion of the fresh concrete.

3.3 BORING FOR PILES

A. Prior to boring, the Contractor shall check the position for each pile and agree the position with the Engineer. All piles shall be constructed having the dimensions not less than the specified dimensions.

B. The Contractor shall ensure that the bore remains stable at all times. Temporary casing or polymer drilling fluid shall be used to support the wall of the bore prior to concreting.

C. Temporary casing shall be clean and free from significant distortion. They shall be of uniform cross-section throughout each continuous length. During concret-ing the casing shall be free from internal projections and encrusted concrete, which might adversely affect the proper formation of piles.

D. Stability of Bore

1. During construction the level of drilling fluid shall be maintained within the cased or stable bore so that it is not less than 1 m above the level of ex-ternal standing groundwater at all times.

2. In the event of rapid loss of drilling fluid during the excavation of the bore, the bore shall be backfilled without delay and the instruction of the Engi-neer shall be obtained before boring at that location is resumed.

3. Adequate precautions shall be taken at all times to prevent surface water or groundwater seepage entering the bore.

E. Piles shall be bored and concrete shall be placed without such delay as would lead to significant impairment of the soil strength. No bores shall be left un-concreted for periods in excess of 24 hours.

F. On completion of boring, the Contractor shall remove loose disturbed or softened soil from the bore. A cleaning process shall be employed before concrete is placed. Debris or accumulated sediment shall be removed using appropriate approved methods, which shall be designed to clean while at the same time minimizing ground disturbance below the bases. Drilling fluid shall be maintained at such levels, throughout and following the cleaning operation, such that stability of the bore is preserved. The thickness of sediment shall be measured at four locations around the perimeter and one at the center of the pile. The maximum allowed thickness of debris shall be 50 mm and the average shall not exceed 25 mm at the time of concreting.

G. If piles are constructed from a working platform, the excavation above concrete level shall not be backfilled until the pile concrete has set to prevent contamination of the fresh concrete.



3.4 DRILLING FLUID

A. Potable water may be used as drilling fluid provided a stable borehole is main-tained at all times.

B. Polymer Slurry (if used):

1. A certificate shall be obtained by the Contractor from the manufacturer of the polymer slurry showing the physical and chemical properties of the slurry. This certificate shall be submitted to the Engineer.

2. Polymer shall be mixed thoroughly with clean fresh potable water to make a suspension, which will maintain the stability of the pile bore for the pe-riod necessary to place concrete and complete construction. The concen-tration of the slurry to produce the desired viscosity shall be in accor-dance with this Specification and the recommendations of the polymer manufacturer.

3. Where saline or chemically contaminated groundwater occurs, special precautions shall be taken to modify the polymer slurry suspension so as to render the slurry suitable in all respects for the construction of piles.

4. Slurry inside the excavation shall be tested as specified below to verify that the slurry properties are within the following specified limits or in ac-cordance with the manufacturer’s written guidelines.

5. Obtain samples from the top and bottom of the shaft and perform the fol-lowing tests once every two hours on each shift, unless otherwise speci-fied. a. Density, by mud density balance in accordance with ASTM D

4380. b. Viscosity, by Marsh Cone Method in accordance with American

Petroleum Institute (API) RP13B – Section 2. c. pH in accordance with ASTM D 4972. d. Sand content in accordance with ASTM D 4381.

6. Immediately prior to concrete placement, obtain a sample of the slurry within 300 millimeters of the bottom of the excavation and test for density, viscosity, and sand content. Modify or replace the slurry if the test pa-rameters of the sample are found to exceed the specified limits. Do not place concrete until the slurry test results meet the specified limits.

PROPERTY LIMIT

Density 1,040 to 1085 kg/m3

Viscosity 50 to 70* seconds/liter

pH 10 to 12

Sand Content 1.5 percent maximum



Fluid Loss 25 cc maximum in 30 minutes

* or as recommended by the polymer manufacturer and accepted by the Engineer

C. The movement of drilling tools up and down the pile bore produces local suction piston effects, by-pass currents, and variations in the level of the drilling fluid suspension due to the displacement volume of the drilling tool and kelly bar. These effects may create scouring and overbreak of the excavation and deteri-orate the slurry and the Contractor shall control the lifting speed of the drilling equipment and use drilling / cleaning buckets with slurry by-pass capabilities to ensure that no adverse effects occur.

D. All reasonable steps shall be taken to prevent the spillage of drilling fluid, either clean or contaminated, onto the ground of the Site. Discarded slurry shall be re-moved from the Site without undue delay. Any disposal of the slurry shall comply with the regulations of the Local Authorities. Under no circumstances shall any suspension be allowed to discharge into any drainage system.

E. At the request of the Engineer, a qualified representative of the polymer supplier or manufacturer shall visit the site and provide verbal and written guidance to the Contractor on the proper use of the slurry to construct the piles as specified here-in.

3.5 CALIPER LOGGING OF PILE BORE

A. Caliper logging of the entire length of pile shall be carried out on 10 percent of the total number of piles prior to concreting, as designated by the Engineer. One half of this 10 percent shall be performed on selected piles in the first 20 piles constructed. The remainder of this 10 percent shall be performed on piles se-lected by the Engineer.

B. Caliper logging shall be performed on the two index test piles.

C. A mechanical caliper having a minimum of three arms shall be used to carry out the logging in accordance with ASTM D 6167. The caliper to be used shall be ca-librated not more than 3 months prior to its use for this project and shall have a resolution not less than 2mm of the measured bore diameter.

D. The caliper shall be calibrated within the temporary casing. The hole diameter shall be recorded at a minimum of every 60 degrees for every 150 millimeters of depth.

E. The Contractor shall submit a hard copy of the log to the Engineer within 24 hours of the measurement having taken place.

F. The bore shall be considered unacceptable if any part of the pile bore has a di-



ameter less than the specified diameter of the pile.

3.6 CONCRETE PLACEMENT

A. The method of placing and workability of the concrete shall be such that a conti-nuous monolithic concrete shaft of the full cross-section is formed.

B. The concrete shall be placed without any interruption as interruption would allow the previously placed batch to have hardened. The method of placing shall be subject to the approval of the Engineer.

C. The Contractor shall take all precautions in the design of the mix and placing of concrete to avoid arching of the concrete in temporary casing, No soil, liquid or other foreign matter which would adversely affect the performance shall be per-mitted to contaminate the concrete.

D. The concrete shall be of the approved workability when placed in it’s final posi-tion and shall remain sufficiently workable for all pile construction procedures to be safely completed.

E. Internal vibrators shall not be used to compact concrete.

F. The concrete shall be placed by tremie pipes. The pipe of the tremie shall be clean and watertight throughout. The pipe shall extend to the base of the bore and a sliding plug or barrier shall be placed in the pipe to prevent direct contact between the first charge of concrete in the tremie and the water or drilling fluid.

G. The tremie pipe shall at all time penetrate the concrete by at least 1.5 meter, which has previously been placed and shall not be withdrawn from the concrete until completion of the concreting. A sufficient quantity of concrete shall be main-tained within the pipe to ensure that the pressure from the concrete exceeds that from the water drilling fluid. The internal diameter of the pipe of the tremie shall be not less than 150 mm. The pipe shall be so designed that external projections are minimized, allowing the tremie to pass within reinforcing cages without caus-ing damage. The internal face of the pipe of the tremie shall be free from projec-tions.

H. Piles shall be concreted as soon as practicable after completion of drilling and cleaning of pile shaft and base. Excavations left open for more than 24 hours for the piles may need to be re-cleaned and have the drilling fluid recycled to the sa-tisfaction of the Engineer.

I. Bores/excavations open for more than 36 hours from start of drilling to finish con-creting will not be acceptable. Approved replacement piles shall be constructed at the Contractor’s expense.



J. Concrete shall not be placed until the pile excavation has been accepted by the Engineer.

K. Piles shall be protected to avoid any temporary loading due to plant and machi-nery for at least 24 hours after concreting.

3.7 DISPOSAL OF EXCAVATED MATERIAL

Disposal of excavated material shall be carried out by the Contractor as necessary to facilitate the Works and to the satisfaction of the Engineer.

3.8 PILE CUT-OFF

A. Pile heads shall be cast to a level above the specified cut-off so that, after trim-ming to remove all debris and contaminated concrete, a sound concrete connec-tion with the pile can be made in accordance with the specified strength and du-rability characteristics.

B. When cutting off and trimming piles to the specified cut-off level, the Contractor shall take care to avoid shattering or otherwise damaging the permanent section of the pile. Damaged sections shall be repaired in an approved manner to pro-vide a full and sound section at the cut-off level.

3.9 PRELIMINARY (ADVANCE) PILES AND STATIC LOAD TESTS

A. Preliminary Test Piles – Static Load Tests

The intent of this part of the test package is to verify skin friction values used in the design of tensile piles, ahead of construction of working piles. The index pile test program shall be as follows:

Type of Pile Testing Number of Tests

Service De-sign Load

(kN) Test Load

(kN) Socket Length

750 mm Diameter bored Piles

Static Load Test 2 See Drawings 200% By con-

tractor

B. Working Test Piles – Static Load Tests

The intent of this part of the test package is to satisfy authority requirements and verify skin friction values. The Contractor shall be responsible for verifying and complying with all current authority requirements. The index pile test program shall be as follows:



Type of Pile Testing Number of Tests

Service De-sign Load

(kN) Test Load

(kN) Socket Length

750 mm Diameter bored Piles

Static Load Test %1 See Drawings 150% By con-

tractor

C. The locations of the index piles will be provided by the Engineer.

D. The test piles shall be installed with the same means and methods proposed for the production piles.

E. The index test piles shall be constructed and tested prior to constructing the pro-duction piles.

F. Test piles shall cure for a minimum of 10 days before testing. Test piles shall achieve a minimum of 80 percent of the 28-day compressive strength before test-ing.

G. The Contractor is responsible for the safe design of the reaction frame, pile rein-forcement, reaction piles and all connections capable of resisting the minimum total pile test load. The minimum clear space between the test pile and reaction piles shall be 2.5 meters. Design sketches and calculations for the design of the reaction frame and reaction piles shall be submitted for review and approval by the Engineer.

H. Testing Standards

Unless otherwise specified, pile load testing is to be carried out in accordance with ASTM D3689 for tension piles.

I. Load Schedule

The tensile loads shall be applied to the test pile in accordance with the Standard Loading Schedule in ASTM D3689. The Quick Load Test Method shall not be accepted.

J. Load Measurement:

The test load shall be measured by the use of load cells.

1. Accurate to within 2 percent of the indicated load and of stable construc-tion.

2. Calibrated prior to commencement of the test. 3. Instrument each test pile with three sets of redundant strain gauges at le-



vels agreed upon with the Engineer.

K. Measurement of Pile Movement

1. Tension test piles are to be instrumented by dial gauges and displace-ment transducers at the pile head and remote survey techniques.

2. Instrumentation: Each test pile is to be provided with: a. Three dial gauges at the pile head b. Optical survey of the pile head

3. The Contractor shall use a suitably integrated monitoring system to the satisfaction of the Engineer for the reading of the load cells and dis-placement transducers.

4. The load at a given load increments is to be governed by the readings from the load cells and not the equivalent pressure as read from the pres-sure gauge attached to the pump.

5. The datum shall be so located that it is not affected by either the test loading or the other site operations.

L. Test Procedures

1. Supervision: The installation of the entire testing system, testing and monitoring, are to be carried out in the full-time supervision of the Con-tractor’s Engineer experienced in pile installation and testing.

2. Delay between installation and Testing: Loading testing of piles and shall not commence until the strengths of materials are adequate to sustain the maximum required test load specified.

3. Load application: upon loading of each test pile to the maximum test load the load shall be removed smoothly and the residual settlement recorded.

4. Recording during loading states: the load, settlement and time shall be recorded immediately upon reaching the load increment and at the inter-vals outlined in Standard Measuring Procedures in ASTM D3689. Should it not be possible to achieve the load increment, readings should be taken as directed by the Engineer.

5. A report on the pile load test shall be prepared and shall include piling records as described in Part 1 of this Specification.

M. Test Layout Equipment:

This section of the report shall include the following:

1. Sketches and photographs showing: the location and size of reaction and loading equipment; deflection measuring equipment; test pile and cap; and position of reference level marks.

2. An assessment of the accuracy of the deflection measurement with par-ticular reference to the movement of the supports of reference beams due to variations in loading or temperature.

3. The results of calibrations of the load measuring apparatus.



N. Reporting

Test Procedure and results: This section of the report shall include the following for axial tension load test:

1. A tabulation of the readings during loading and unloading of the pile, to-gether with relevant times. It shall be clearly indicated whether the results are uncorrected readings or reading after corrections for calibration. Movement of datum points and other influences.

2. A graphic representation to the test results in the form of either a load def-lection curve or time deflection curve where sustained loading increments are made.

3. An assessment of the effect of the reaction system on the deflections; and the ultimate tensile capacity, where appropriate.

4. Copies of all results to be supplied in a recognized spreadsheet format such as Excel.

O. Information to be supplied:

1. Relevant experience 2. Pile construction procedure, reinforcement and concrete strength. 3. Pile load reaction system to be adopted. 4. Details of instrumentation to be used. 5. Full details of any non-conformance and alternatives proposed. 6. Proforma test records. 7. Typical report showing how the information to be provided would be pre-

sented. 8. Name and CV of full-time supervising Engineer for the testing.

P. Quality Plan: The successful tenderer will be required to submit a quality plan for the testing regime for approval prior to commencement of testing.

3.10 QUALITY CONTROL

A. Drilling Fluid – Sampling and testing of drilling fluid shall be carried out in accor-dance with Subsection – Drilling Fluid.

B. Concrete – Sampling and testing of concrete shall be carried out in accordance with Subsection – Concrete for Piles.

C. Pile Caliper Logging – Caliper logging shall be carried out in accordance with Subsection – Caliper Logging of Pile Bore.

3.11 POST CONSTRUCTION INTEGRITY TESTING

A. Summary



Installation of the specified equipment and materials and preparation for the Crosshole Sonic Logging (CSL) and Impulse Response Spectrum (IRS) testing shall be the responsibility of the Contractor. The CSL and IRS testing and analysis will be performed by an Independent Testing Agency (ITA) contracted by the Contractor.

B. Frequency of Post-Construction Integrity Testing

1. Cross-hole sonic logging shall be performed on 20 percent of the piles. The two index test piles shall be subject to CSL testing prior to performing the load tests. The first ten piles shall be subject to CSL testing. If all elements are accepted, the remaining piles shall be tested at a frequency of one for every five production piles. Should deficiencies be identified af-ter the first 10 piles the frequency will be increased, at the discretion of the Engineer.

2. IRS testing shall be performed on every bored piled, including the two in-dex test piles prior to performing the load tests.

C. Cross-Hole Sonic Logging

Post construction integrity testing shall be performed by Cross-Hole Sonic Logging.

1. Access tubes for cross-hole acoustic logging shall be placed on the rein-forcing cages designated for testing.

2. The access tubes for cross-hole acoustic logging shall consist of Sche-dule 40 steel pipe conforming to ASTM A 53, Grade A or B, Type E, F, or S. The inside diameter shall be at least 40 mm.

3. A minimum of four tubes shall be provided for each pile designated for testing.

4. The access tubes shall be installed equally spaced around the periphery of the shaft, unless otherwise specified.

5. The access tubes shall be clean internally and externally. Surface con-taminants, such as but not limited to, grease or thread cutting, which would impair the bond to the concrete, shall be completely removed be-fore installation of the access tubes using a de-greasing agent.

6. Heavy flaking or scale rust shall be chipped or wire-brushed to remove loose particles.

7. All access tubes shall have a round, regular inside surface free of defects and obstructions, including all pipe joints, in order to permit the free, un-obstructed passage of probes to the bottom of the tubes. The access tubes shall be watertight, free from corrosion and free of deleterious ma-terial on the outside that can prevent bonding with the concrete. All access tubes shall be fitted with watertight caps on the bottom and top.

8. To permit full penetration of the concrete through the reinforcing cage, and complete coverage of the access tubes, spacers shall be installed on the cage to ensure concentricity within the shaft.



9. The access tubes shall be filled with water immediately before concrete placement.

10. All access tubes shall be capped before concrete placement to avoid the risk of falling debris or spilled concrete entering and blocking the tubes.

11. Prior to the beginning of down-hole logging, the Contractor shall assure that the test probes can pass through every tube to the bottom. If a tube is obstructed, the Contractor shall, at the Contractor’s expense, core a hole within the drilled shaft near the obstructed tube to the depth of the obstructed tube that is large enough to accommodate the probe for the full length of the hole.

12. The coring equipment, coring procedure and location of the core hole shall be approved by the Engineer prior to beginning the coring process. The coring method shall provide for complete core recovery and shall mi-nimize abrasion and erosion of the core. The core hole shall be placed at a position in the shaft that will not produce damage to the reinforcing steel in the shaft. The core hole shall be logged, voids or defects indicated on the log and the log submitted to the Engineer. Cores shall be preserved and made available for inspection by the Engineer. The core hole will be treated as an access tube and down-hole testing shall then commence.

13. If a defect is observed, the Contractor shall pay for all coring costs and shall repair the shaft at its expense, as above.

14. Upon completion of all tests involving access tubes, the access tubes and core holes shall be filled with grout having strength properties equivalent to or better than those of the drilled shaft concrete.

15. The ITA will submit the results, analysis and interpretation of the CSL testing for each pile tested along with the criteria used to evaluate the re-sults, to the Engineer for approval. The Engineer will determine final ac-ceptance of each pile, based in part on the CSL test results and analysis for the tested pile as well as other pertinent information and test data and will provide a response to the Contractor within three working days after receiving the test results and analysis.

D. Impulse Response Spectrum Testing

1. The Contractor shall give all available details of the ground conditions, pile dimensions and construction methods to the Engineer in order to faci-litate interpretation of the tests. A written plan indicating the testing equipment, methods, interpretation and criteria for evaluating the pile in-tegrity will be provided by the ITA to the Engineer for approval.

2. The testing will be performed after the shaft concrete has cured a mini-mum of 7 days or after concrete strength achieves at least 75 percent of the design value, whichever occurs earlier. Additional curing time prior to testing may be required if the shaft concrete contains admixtures, such as set retarding admixture or water reducing admixture. The additional cur-ing time prior to testing required under these circumstances shall not be grounds for additional compensation or extension of time to the Contrac-



tor. 3. The Contractor shall clear the pile head of surrounding soil and any

standing water. The Contractor shall remove laitance, grout or contami-nated material utilizing a small chisel, bush-hammer or similar method so that a surface is provided that is acceptable to the ITA.

4. The use of a jack hammer, which may cause cracking at the pile head, is not allowed.

5. A minimum of one, 100-mm diameter patch at the center and one 75-mm patch near the periphery of the pile shall be cleaned and prepared by the Contractor using the methods described above. The prepared areas shall be finished smooth, flat and at right angles to the axis of the pile.

6. The Contractor shall provide a minimum of 0.6 meter vertical clearance to allow for the performance of the test.

7. The Contractor shall provide free access to the center of the pile head for IRS testing by the ITA.

8. The ITA will submit the results, analysis and criteria used to evaluate the IRS testing for each pile tested to the Engineer for approval.

E. Acceptance Criteria

1. The Engineer will determine the acceptance of the CSL and IRS test re-sults and will provide a response to the Contractor within three days after receiving the test results and analysis submittal from the ITA.

2. For all piles determined to be unacceptable, the Contractor shall submit a plan for remedial action to the Engineer for approval. All modifications to the dimensions of the piles, as shown in the Plans, required by the re-medial action plan shall be supported by calculations and working draw-ings. All remedial correction procedures and designs shall be submitted to the Engineer for approval. The Contractor shall not begin repair opera-tions until receiving the Engineer’s approval of the remedial action plan. The design and construction of the remedial measures shall be at the Contractor’s sole expense with no additional cost to the Owner.

3. At the Engineer’s direction, the Contractor shall drill core holes in any pile of questionable quality (as determined from CSL or IRS testing and anal-ysis or by observation of the Engineer) to explore the pile condition.

4. Prior to beginning coring, the Contractor shall submit the method and equipment proposed for use to drill and remove cores from pile concrete to the Engineer and receive the Engineer’s written approval. The coring method and equipment shall provide for complete core recovery and shall minimize abrasion and erosion of the core.

5. If a defect is confirmed, the Contractor shall pay for all coring costs. If no defect is encountered, the Contractor will be paid for all coring costs.

3.12 DOWNGRADED PILES

A. Any piles damaged in any way, or not installed within the specified position or



vertically tolerance, or elements that failed to attain the maximum specified load-ing during load tests shall be classified as down-graded piles.

B. Down-graded piles shall be evaluated, and if necessary rejected, at the discretion of the Engineer and replaced or supplemented with substitute piles by the Con-tractor at his own expense. At the sole discretion of the Engineer, the pile caps and any required compensating pile shall be constructed to a modified design proposed by the Contractor to account or the variation in pile position or align-ment. The cost and time of replacement, including all direct and consequential costs in modifications required, shall be borne by the Contractor.

3.13 DEVIATION FROM SPECIFICATION

If the contractor proposes any deviations from the above requirements or procedures outlined in the specified references, the contractor should detail the deviation requested and the reasons for the deviation for review by the Engineer.

3.14 DISPOSAL

Upon the completion of the Works the Contractor shall clear away and remove from the Site all constructional plant, equipment, surplus materials, rubbish, etc. and leave the whole of the Site and Works clean and in good condition to the satisfaction of the Engineer.

END OF SECTION 316300

specification bored piles

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standard specifications

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structural concrete

report c144 integrity

astm d6167 standard

astm d5753 standard

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