Shaking table tests on pile group-soil-structure interaction to seismic loading on liquefied ground

In order to study the laws of pile group-soil-structure interaction under seismic actions, dimensional analytical method is used to design the pile group-pier model shaking table tests. Then foundation acceleration response, pile-pier acceleration response and the law of pore water pressure response are discussed by inputting El Cenro seismic waves with amplitude of 0.15g and 0.5g respectively. The test results indicate that (1) when small earthquake is input, linear characteristics of foundation dynamic deformation are evident, mainly reflecting the dynamic amplification effect on seismic waves and the gradual increase of acceleration response from bottom to top; when large earthquake is input, dynamic deformation of the foundation shows obvious non-linearity and the laws of acceleration response are diverse; (2) pile-pier acceleration response mainly concentrates in low-frequency band with complicated laws; (3) buried depth and pile spacing impact greatly on the variations of pore water pressure of the foundation, also, the pore pressure decreases while pore pressure ratio increases with the reduction of buried depth, and the pore pressure grows with the reduction of pile spacing, which causes a certain degree of pore water pressure gradient around the pile. Shaking table tests can reproduce the macroscopic phenomena of natural earthquake action well and are a good approach to study the pile-soil-structure dynamic interaction laws on liquefied ground.