Probabilistic Analysis of Buried Pipeline Response Subjected to Fault Crossing

Deterministic analysis aims to demonstrate that a facility is tolerant to identified faults/hazards that are within the ‘design basis’, thereby defining the limits of safe operation. However, it cannot address the risk and uncertainty associated with it adequately, especially when the degree of uncertainty is high, like in seismic events. Deterministic analysis and design can provide an appropriate degree of safety to a set of loading parameters, whereas, a probabilistic analysis and design can provide a rational design based on acceptable risk and reliability of the system performance. In this paper, the major variables that greatly influence the performance of buried pipelines subjected to fault crossing has been identified and their coefficient of variance were selected. Monte-Carlo simulation has been implemented to find out the pipeline response in terms of maximum strain in the pipeline. Different cases were taken by keeping coefficient of variance (COV) constant while changing the subsequent parameters individually as well as combined. For various state of risk, the probabilistic distribution of pipeline strain has been obtained and finally a factor of safety (FOS) is calculated as the ratio of characteristic mean response and deterministic mean (response), for various probability of exceedance (acceptable risk).