A large-scale shaking table model test for acceleration and deformation response of geosynthetic encased stone column composite ground

摘要

Effective mitigation of seismic-induced ground hazards requires an improved understanding of ground response in terms of earthquake wave propagation and ground deformation. Here, this paper examines the effects of geosynthetic-encased stone columns (ESCs) and ordinary stone columns (SCs) on the acceleration amplitude and frequency content responses of sand profiles, and the deformation of the ground using a large-scale shaking table model test. The model was excited by 15 shaking events including El Centro motion, Wenchuan Qingping motion and Kobe motion with peaks ranging from 0.1 to 0.9 g. The results indicate that the ESCs more significantly amplify surface accelerations compared to the SCs in the frequencies ranging from 10 to 17 Hz and from 2.5 to 9 Hz. The horizontal peak acceleration values in the ESCs composite ground are approximately twice those of the SCs composite ground. The acceleration response of the ground is influenced by the applied acceleration peak and frequency content, reinforced type, and structure. After the seismic excitation, the ESCs composite ground develops much narrower surface cracks distributed in a larger area compared to the SCs.