Response of Deeply Buried Pipeline Laid through a Fault to Random Ground Motion

A simple model is used to study the response of deeply buried pipeline laid through a fault to random ground motion, in which the fault is simplified as a two-media site and seismic ground motions are considered as stationary stochastic processes. The cross-PSD function is calculated by wave propagation theory and random vibration theory. Then, the cross-PSD function, regarded as seismic input, is used to calculate the seismic response of deeply buried pipeline. The results show that: (1) the peak normal stress is always larger than the peak shear stress; (2) the peak normal stress for incident P-wave or SV-wave, which appears in the pipeline in the soft media, is larger than the one for incident SH-wave, which appears in the pipeline in the firm media; and (3) the peak shear stress for incident SH-wave is larger than the one for incident P-wave or SV-wave, and the peak shear stress always appears in the pipeline in the firm media.