Within the scope of urban lifeline service area

the seismic failure of buried pipelines is dependent on each other in pipeline network system

which is caused by similar structural parameters of buried pipelines with same materials and spatial correlation of ground motion intensities.This paper describes a novel stochastic simulation strategy of buried pipeline network seismic reliability considering correlated failure of pipelines.The spatial correlations of ground motions at different sites are expressed by the correlation coefficient between residuals of attenuation relation of PGVS.The failure probabilities of pipeline segments

affected by spatial correlated ground motions

are calculated by Poisson distribution formula using the mean occurrence rate model.According to the relationship between the joint distribution and marginal distribution

correlated coefficients of pipeline failure events are deduced then.In the Monte Carlo simulation model for calculating pipeline network reliability

the seismic failure events of pipelines are taken as dependent random variables firstly

the dependent random variables are transformed into independent random variables by orthogonal transformation then.The validity of the proposed model is verified by pipeline network case study affected by scenario earthquakes.The influence of pipeline failure dependency on network reliability is also analyzed.