A series of large-scale shaking table tests were carried out to investigate the seismic performance of different cement-soil reinforced pile groups in liquefiable sands. Specifically, sinewave scanning was performed on three cement-soil reinforced 3 x 3 pile groups and one conventional (unimproved) 3 x 3 pile group. In this study, the bending moment of group piles, the horizontal displacement of the superstructure, pore water pressure into soils, and the settlement and acceleration response of piles and the ground under different earthquake intensities were recorded. The natural frequency of the ground and the dynamic stress-strain relationship of the soils around piles were obtained. The results show that the acceleration response of the improved pile groups before soil liquefaction is significantly smaller than that of the unimproved pile group. However, the acceleration attenuation of the unimproved pile groups after soil liquefaction is substantially greater than that of the improved pile group. In addition, the lateral displacement of the superstructure, the settlement of pile heads, the bending moment of pile shafts, and the dynamic shear strain of the soils around piles in improved cases are all smaller than those in the unimproved case. In particular, the improved cases significantly suppressed the pile bending moment at the interface between the liquefied layer and the non-liquefied layer. The spatial layout of cement-soils significantly impacts the natural frequency and stress changes of the pile-soil Winkel elastic foundation beam systems.

来源平台：INTERNATIONAL JOURNAL OF CIVIL ENGINEERING