Modified Factor for Segmented Pipes in Chinese Pipe Seismic Design Code Based on Probability Density Evolution Method

Abstract

Buried pipes are important components of water and gas supply systems. A series of investigations indicate that buried pipes in China suffered serious damages in previous strong earthquakes. Therefore, seismic response analysis and design of buried pipes is an important research topic. In this study, a program is proposed to give the modified factors for segmented pipes in Chinese pipe seismic design code based on the probability Density Evolution Method (PDEM). A stochastic analysis method based on a finite element model of buried pipes and the Probability Density Evolution Method (PDEM) is proposed to determine probability density functions of seismic responses of buried segmented pipes. Then, seismic responses with different guaranteed rates can be derived and adopted for the design of buried pipes in preparation for earthquakes. Stochastic seismic responses of three segmented pipes buried in four sites are calculated using the proposed method. Joint deformations with guaranteed rates of 50%, 80%, 90%, 95%, and 99% are then summarized, and the modified factors for segmented pipes are derived to modify the Chinese code.