Dynamic load testing shall be performed during pile driving work. Wave speed shall be measured for pile prior to setting up the pole for loading test. When measuring the wave speed, pile shall be laid down horizontally on flat ground, and measure shall be taken to prevent contact with other piles.
Pile shall be driven down to the depth of reaching ultimate bearing capacity. During driving of pile, the stress acting on pile shall be monitored and controlled to stay below the allowable value.
When necessary, striking energy transmitted to pile shall be reduced to maintain the stress below the allowable value by adding cushion or by reducing the output hammer energy.
After completion of dynamic loading test, the Contractor shall report the results to the Engineer for confirmation and shall determine the number of pile and driving depth for the Work.
When passed 24 hours from the completion of dynamic pile load testing, test instrument shall be attached to the pile and pile shall be re-driven. Penetration depth of pile during re-driving shall be less than 150mm, and the number of hammering shall be less than 50 times.
QUALITY CONTROL
For observing and recording the test method and results, the Contractor may employ independent testing institute. Testing recording shall include the type and size of testing equipments, methods of verification and recording, test results, method of pile driving and suggestions/recommendations.
Dimensions of tested pile and movement or twist of pile form testing shall be precisely recorded. Dynamic load testing shall be carried out during execution of pile driving.
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