Seismic analysis of buried pipeline in a 3D soil continuum

Abstract

An efficient numerical approach based on both boundary and finite element methods is developed in this work. This development is capable of realistic three dimensional analyses of soil-structure interaction problems in the real time domain and is specifically tailored to buried lifelines. In particular, boundary elements are used in a surface-only representation of the buried cavity problem for determining influence functions at the cavity/pipeline interface for the case of prescribed motions at the control point. Subsequently, these influence functions are converted into loads and are used as input to a finite element model of the pipeline. Following careful validation studies, the present methodology is applied to a real site with known seismological characteristics and the results are gauged against empirical design formulae. It is shown that the seismically induced stress state in a buried pipeline is more pronounced in the case of transverse vibrations than in the case of longitudinal vibrations.