Section 02374 DRILLED PIERS - LOAD TESTING

Section 02374

DRILLED PIERS - LOAD TESTING

_{PART 1 – GENERAL}

1.1 THE REQUIREMENT

A. The Work covered under this section consists of furnishing all plant, labor equipment, appliances, design and materials and performing all operations in connection with dynamic and static load testing of piles. Installation of piles is covered under Section

02373 – Drilled Piers. Pile load testing shall be designed to verify the required load carrying capacity for the installation of production piles.

B. The CONTRACTOR shall retain a Professional Engineer registered in the State of California with experience on at least five similar projects to supervise or perform all functions associated with performing the static pile load tests which shall be observed by the ENGINEER. The CONTRACTOR’s professional Engineer shall evaluate the test results in accordance with these Specifications. The results shall be sealed by the CONTRACTOR’s Professional Engineer and submitted to the ENGINEER for review and acceptance.

C. Piles required to be tested:

1. Perform Static Load Testing in accordance with Article 3.1 on the following piles. The piles selected for testing shall be production piles acceptable to the ENGINEER, or extra piles placed specifically for testing at locations beneath the indicated structures acceptable to the ENGINEER. Reaction piles shall be extra piles placed specifically for testing and shall not be used for production piles.

a. Two (2) piles under Zone H (Typical 130 kip vertical capacity)

b. Two (2) piles under Zone A (Typical 160 kip vertical capacity)

c. Two (2) piles under Zone E and Zone G (Typical 200 kip capacity)

d. Two (2) piles under Zone C (Typical 240 kip capacity)

2. Tension Load Testing. Not required unless specifically requested by the ENGINEER; except that deformation dial gages shall be installed on each of the reaction piles and be monitored during load tests.

3. Lateral Load Testing. Not required unless specifically requested by the

ENGINEER.

1.2 RELATED WORK SPECIFIED ELSEWHERE A. Section 02373, Drilled Piles.

1.3 SUBMITTALS

A. The CONTRACTOR shall submit at least the following to the ENGINEER in accordance with the General Requirements.

1. A dimensional sketch of the loading arrangement.

2. Testing and measuring equipment used in the load test, including jack, deformation dial gages, pressure gauge, and load cell calibrations.

3. Proposed test pile locations.

4. Proposed reaction pile locations.

5. Certifications of applied loads.

6. Load test records and report.

B. Locations of test and reaction piles shall be acceptable to the ENGINEER.

1.4 REFERENCE SPECIFICATIONS, CODES, AND STANDARDS

A. Comply with the reference specifications of the General Requirements.

B. Comply with the current provisions of the following Codes and Standards.

1. Commercial Standards.

ASTM D1143

ASTM D3689

PART 2 – PRODUCTS

2.1 STATIC LOAD TESTING

A. All equipment and materials required for load testing of the test piles shall be furnished by the CONTRACTOR. Load test piles may be incorporated into the Work as permanent piles provided the piles meet the required capacity and are undamaged. Permanent piles shall not be used as reaction piles.

B. Load testing shall consist of a minimum of 2 axial compressive load tests.

C. The load test apparatus shall be capable of sustaining loads at least 40 percent greater than the maximum anticipated load. The capacity of the loading apparatus shall be sufficient to operate under the anticipated loading without incurring damage or interrupting the load test. A sketch of the proposed method of testing shall be submitted to the ENGINEER for acceptance before the test piles are installed.

D. The pistons shall have sufficient strokes to accommodate the anticipated test beam deflections of hydraulic jacks and test pile movements, and the pressure gauge shall be certified for accuracy by an independent testing laboratory at the expense of the CONTRACTOR. The hydraulic jack shall have a capacity sufficient to preclude the use of multiple jacking systems. The applied loads shall be verified and recorded by a calibrated load cell certified for accuracy of at least 2 percent of the applied load by an independent laboratory. Copies of the certifications shall be submitted to the ENGINEER.

E. The test piles shall be installed at the same cutoff elevation as the production piles.

2.2 REACTION PILES

A. The CONTRACTOR shall install reaction piles as required around the test piles.

B. Reaction piles shall be drilled piers similar in construction to permanent piles; but after testing, reaction piles shall be abandoned in place and not considered part of the permanent structure.

C. The spacing, reinforcing, and number of reaction piles shall be selected by the

CONTRACTOR to coordinate with the pile testing apparatus and procedures. D. All information on the reaction piles shall be submitted to the ENGINEER.

PART 3 – EXECUTION

3.1 STATIC LOAD TESTING

A. Axial Compressive Load:

1. The axial compressive load test and report of the results shall be conducted and written in accordance with ASTM D1143, except as modified or supplemented by these specifications.

2. Axial compressive load testing shall be conducted in accordance with ASTM D1143, 5.6 – Quick Load Test Method for Individual Piles. Load increments shall be based on the working load carrying capacity (design load) for the pile, and the full test load shall be at least twice the working load carrying capacity.

B. Net Settlement:

1. Net settlement of the test pile shall be recorded as a function of load applied and time. Net settlement shall be defined as the elevation difference of the butt prior to loading and after unloading of the test pile. Measurement of movement shall be in accordance with ASTM D1143, 6.4 – Readings for Quick Load Test Method.

C. Load Test Acceptance:

1. Pile failure shall be defined as a net settlement exceeding 0.01 inch per ton of the test load, but not exceeding 0.5 inches. If any test pile experiences a net settlement in excess of that defined by pile failure at or before the full test load has been attained shall be rejected, the pile load test shall be halted, and the test results submitted in accordance with the load test records paragraph of this specification.

D. Load Test Records:

1. Load test data shall be reduced in both numerical and graphical form. The reduced data shall be submitted to the ENGINEER for review and acceptance. Six copies of the load test report shall be submitted on forms acceptable to ENGINEER. In addition to pile installation records required by Section 02373 test pile data recorded shall include, but not be limited to, the following:

a. Test pile number and location. b. Date and time of testing.

c. Load and settlement readings. Both applied loads and loads recorded by the load cell shall be submitted for all settlement readings.

d. Time-load-settlement curve.

2. All data recorded shall be certified as correct.

3.2 OTHER PILE LOAD TESTING

A. Tension Capacity: In the event design tension pile capacities are required to be tested, the tension capacity for individual piles will be determined in accordance with the requirements of ASTM D3689 or an approved method of analysis based on a minimum safety factor of 3. Load test records shall be similar to Article 3-1.D.

B. Lateral Capacity: In the event design lateral pile capacities are required to be tested, the ENGINEER will determine an appropriate test method.