Seismic Pile–Soil Interaction Analysis Based on a Unified Thixotropic Fluid Model in Liquefiable Soil

Abstract

One of the challenges to the analysis of interactions between soil and piles in lateral spreading is the modeling of the progress generated by excess pore pressure and soil strength and stiffness degradation. In this paper, a pile–soil interaction analysis method that introduces the thixotropic-induced excess pore pressure model (TEPP) to describe the progressive development of the stress–strain rate connection of liquefying soil is proposed. The reliability of the method was verified by comparing the calculated results with that of the shake table test. Then, the parametric analyses of soil–pile interactions were carried out. The results show that the bending moment and horizontal displacement of pile foundations increase with the increase in superficial viscosity and inclination angle of the site. The horizontal dislocation and bending moment of the pile foundation increase with the decrease in loading frequency as a result of the property of amplifying low-frequency loads and filtering high-frequency loads of liquefied soil.