Field Test Study on Construction Disturbances of Driven Pile and PGP Pile

Abstract

The pre-bored grouted planted (PGP) pile has been more and more used in recent years, but its precise disturbance effect in soft soil areas has not been studied deeply. Therefore, a comparative field test for the disturbances by PGP pile and driven pile construction in deep soft ground was carried out. It revealed that the excess pore pressure caused by the two kinds of piles decreases with the increase of radial distance, and the influence range is less than 7.5 d (d is pile diameter). The maximum excess pore pressure generated by PGP pile construction is about 100 kPa smaller than that generated by driven pile construction. The comparison of the soil pressure and lateral displacement between the two piles is related to the depth and soil type. The typical result is that the soil pressure caused by PGP pile construction is half that of the driven pile, and the maximum lateral displacement of the PGP pile is 50.7~53.8% of that of the driven pile. The noise generated during PGP construction was lower but continuous, and the maximum value at the same distance was reduced by 8 to 15% than the driven pile. The test results reveal the construction disturbance effect of PGP pile and provide a reference for the selection of pile construction method in soft soil areas.

Keywords

• saturated soft clay
• driven pile
• pre-bored grouted planted pile
• field test
• pore water pressure
• soil squeezing effect