Analysis of the transient response of vertically loaded single piles by time-domain BEM

Abstract

A quasi-linear time marching time domain boundary element method is developed for the analysis of the transient dynamic response of single piles in a layered soil under a time-dependent vertical force. The pile and the layered soil are modelled by finite elements (beam elements) and cylindrical coordinate time-domain boundary elements, respectively. The field quantities of the soil such as the displacements and tractions are assumed to vary linearly along the depth. In the time domain, the field quantities for both the soil and pile are interpolated by quadratic functions in terms of corresponding values at time ( n − 1)Δ t, ( n − 1 2 )Δ t and nΔ t. Expressing the field quantities at ( n − 1 2 )Δ t as the average of the values at ( n − 1)Δ t and nΔ t, a quasi-linear scheme has been developed for the time-marching process. Numerical examples of response of pile due to different types of dynamic loadings are reported to demonstrate the accuracy and stability of the proposed method.