Nonlinear 3D finite element analysis of a shear-wave vibrator-ground interaction system

Abstract

Shear-wave vibrator is a type of equipment usually employed for natural gas exploration, consisting of a vibrating machine which applies dynamic loads to the surrounding soils in order to ease the extraction of the gas. Detailed numerical simulations of these devices are scarce in the literature. Thus, in this paper, a nonlinear 3D finite element numerical simulation has been conducted to investigate the main features of the dynamic response of the vibrator. Nonlinear aspects such as baseplates-soil interaction, soil plasticity, and non-reflect boundary conditions, usually neglected in previous simulations, are considered in this model. The stress distribution, plastic deformation, shear wave propagation, ground force and energy characteristics of the vibrator-ground system are analyzed in detail. Based on the achieved results, an evaluation criterion is developed to quantify the performance of the shear-wave vibrator. Moreover, a parametric analysis has been conducted and the effects of some system parameters, such as excitation frequency, different soil properties and embedded depth, are analyzed and discussed in detail. The results can provide a reference for operating or optimizing the design of shear-wave vibrators.