Kinematic response of vertical and batter pile groups in non-linear soft soil

Abstract

This paper presents a comprehensive numerical study on kinematic response of vertical and batter pile groups in soft soil, where soil non-linearity, batter angle, pile spacing and excitation frequency are related to pile-cap displacements, rotations, maximum pile moments, shear forces and axial forces. The finite element model is constructed in OpenSees MP, and parallel computing is utilized for a better (faster) performance. Results reveal that soil non-linearity has a profound impact on the kinematic interaction. Increasing batter angle decreases horizontal displacements but increases rotations. Batter pile groups yield lower spectral accelerations compared to vertical pile groups. For high PGA, the spectral accelerations of the pile-cap may be lower compared to the spectral acceleration of the seismic input motion. Estimation using non-linear interaction factors conservatively estimates pile-cap displacements and rotations, while roughly captures the effects with respect to batter angle and frequency content within the specified framework.