Seismic Risk Analysis of Buried Pipelines

Abstract

A method is proposed for the seismic risk anlysis of buried pipelines, in which an analytical procedure is developed to estimate the annual probability of occurrence of different damage states (damage indexes) in a component segment (including pipe intersection) of the general network system for pipelines considering earthquake motions as stationary random processes. In the analysis described, the power spectral density functions (PSDFs) of ground accelerations characterizing the earthquake motions are related to the earthquake intensity measured in Modified Mercalli Intensity (MMI) scale. The expected peak values of stress developed at various sections are determined for each earthquake intensity. The annual probability of occurrence of different damage states is obtained by combining a damage probability matrix with the annual probability of occurrence of different levels of earthquake intensity. The proposed method is used to conduct a numerical study to show the effect of types of soil, the pipe end conditions, the types of intersections, the pipe radius, and the angle of incidence of earthquake wave with respect to the global coordinates of the pipeline system on the damage probability of the component pipe segment.