E-Defense shaking test and pushover analyses for lateral pile behavior in a group considering soil deformation in vicinity of piles

Abstract

Large-scale E-Defense shaking table tests were performed using a 3 × 3 pile group in dry sand layers to clarify dynamic lateral pile behavior in a group. The mechanism behind the seismic response of piles in a group was investigated based on the earth pressure acting on piles and soil deformation in the vicinity of the pile and that in the free field. The test results indicated that soil deformation in the vicinity of piles is the key factor influencing group effects during an earthquake. To evaluate pile response in a group, a new concept involving static pushover analyses of pile groups considering soil deformation in the vicinity of piles was developed. The estimated pile response showed reasonable agreement with the experimental results obtained without using p-multipliers. The proposed method could evaluate pile responses considering soil and pile properties, loading levels, pile spacing, and kinematic effects. Thus, the proposed method could help better estimate pile response during earthquakes.