Analytical Derivations and Numerical Verifications on the Asymmetric Dynamic Responses of the Buried Steel Pipelines Under Seismic Active Faults

Abstract

The seismic ground movements may lead to significant bending, tensile, and compressive strains to the buried steel pipelines. This study concerns the dynamic behavior of the buried pipeline at its yielding state to offer preliminary design criteria in the geohazard region. An analytical scheme is proposed to assess the responses of the pipelines under a normal fault or a strike-slip fault. A piecewise function is assumed to describe the deformed S-shaped pipeline under the seismic fault. Then, the explicit strain and displacement are obtained by considering the asymmetry of curvature and pipeline-soil interaction. Moreover, the deformed length and yield displacement are predicted explicitly based on the first yielding theory of the classical beam for both asymmetric and symmetric cases. In addition, the proposed analytical results, characterized by the deformed shape and the yield displacement, are verified efficiently by developing a three-dimensional (3D) finite element model (FEM) in the present study, as well as other predictions elsewhere. It is found that the present study offers a good reference for strength evaluation and failure analysis of pipelines subjected to a normal fault or a strike-slip fault.