关键词: 土塞效应, 振动特性, 现浇薄壁管桩, PCC桩, 导纳曲线

Abstract: Based on ABAQUS, a three dimensional finite element model was established to simulate the low-strain transient dynamic response of PCC pile. The velocity responses on the pile top in time and frequency domains are obtained under various soil plug ratios and friction coefficients of pile wall. The results show that: ①with the increasing of soil plug ratio, the first reflection peak amplitude in the velocity-time domains curves decreases while still being affected by the three-dimensional effect; ②with the increasing of friction coefficient, the amplitudes of the first and second order reflection peaks decrease gradually, showing a relative small and linear attenuation for the first order wave and a relative significant and nonlinear attenuation for the second order wave respectively. The wave shape separates before the second order reflection peak occurs; ③due to the soil plug effect, the wave velocity decreases in the soil plug area and the stronger the soil plug effect is, the more significantly the velocity reduces; ④the coupling of longitudinal, transverse and bending vibration of the PPC pile is weakened by the soil plug effect, hence the formant amplitude in PCC admittance curve goes down.

Key words: soil plug effect；vibration characteristic, cast-in-place thin-walled pipe pile, PCC pile, admittance curve