Field test on internal soil vibrations induced by resonance-free steel pipe pile driving

There is an increasing demand for the use of resonance-free steel pipe pile (RFSPP) adjacent to above- and below-ground structures in urban areas, but few field tests have been conducted on internal soil vibrations caused by RFSPP driving. In this paper, the vibration velocities within the soil and at the ground surface are investigated by a field test. The results confirm that the effect of internal soil vibration is larger, which is consistent with the published numerical results. The internal influence radius is around 1.6 times the surface influence radius, in which they are 7.1 and 4.6 times pile diameter (0.7 m) in the field test, respectively. The vibration response is more significant for the stiff soil. Strong radial vibrations may loosen the soil adjacent to the pile and squeeze the soil slightly further away, which can be preliminary validated by published studies. The loosened soil zone helps to reduce the pile side friction. This work can contribute to a better understanding of the vibration effects of the RFSPP driving.