Dynamic FEM analyses on behavior of SCP improved ground with various geometry

Abstract

Liquefaction of foundation soil attributes significant damage to infrastructures. The sand compaction pile method is one of the countermeasures against liquefaction to densify the ground by installing dense sand piles. In recent years, an innovative method has been developed to install the sand piles at various geometric form into the ground. However, the effects of the geometric forms on the response and deformation behavior of the improved ground are not well understood. The authors have studied the effect of SCP improved ground geometry on the seismic behavior of embankment by physical modeling and numerical analyses. The centrifuge model test results were reported already. In the analyses, a series of dynamic FEM analyses is carried out to investigate the behavior of unimproved ground and SCP improved grounds with vertical geometry and inclined geometry. From the analyses, the unimproved ground is liquefied during shaking and the foundation ground is experienced large lateral deformation, which induces significant settlement of embankment. For SCP improved grounds, although liquefaction is not prevented, the significant reduction in foundation ground deformation and embankment settlement can be observed. The inclined SCP improved ground shows the larger reduction of the embankment settlement than the vertical improved ground.