(Based on Marina Barrage Project experience)

Bored pile integrity test using PDA (Pile Driving Analyser) test

PDA test - on site recording instrument

SPT (Standard Penetration Test) - to determin the OA layer by a free fall hammer weighing 63.5kg on to a drive head from a height of 760mm. The number of such blow (N) necessary to achieve a penetration of the split-barrel sampler of 300mm is regarded as the penetration resistance (N). If N<=100 blows/30cm, the OA layer is considered reached.

Kentledge test - to determin the pile working load

Kentledge test - use hydrolic jack and strain gauge to record the settlement of test pile and determin the pile quality. The test pile is loaded in 2 cycles, first to 1.0 time of its working load and then to 2 times of its working load, maintaining for 24h and unload. The maximum and residual settlement are recorded respectively.