Multi-hazard failure probability analysis of gas pipelines for earthquake shaking, ground failure and fire following earthquake

Abstract

This paper was aimed to provide a quantitative failure probability analysis for multiple hazards. To achieve this, the 1724-kPa (250 Psi) gas pipelines of one of the district neighborhoods of Tehran metropolitan are analyzed to establish the probability of damage against earthquake, fire and liquefaction as a multi-hazard case study. The pipeline is approximately 4 km long and is divided into 14 segments, each of which has 300 m length. We used probabilistic analysis to identify the sources of earthquakes in the area. We calculated the probability that an earthquake with a given maximum magnitude will occur, the probability of liquefaction, that of post-earthquake fires, and the probability of pipeline failure for each segment. In order to take into account uncertainty in the location of epicenters, different points on the North Ray fault were randomly selected as epicenters, and the analysis was carried out for each point. Finally, based on the proposed method, the upper bound of failure probability of the main pipeline resulting from multiple hazards was estimated to be 65.7 %. If ductile pipelines were installed, this amount could be reduced to 32.7 % which shows a reduction of 51.79 % of the upper bound of failure probability.