Strength Analysis of Buried Polyethylene Pipeline Under Ground Subsidence Considering Multivariate Influence

Due to the combined effects of natural and human factors, the ground subsidence is aggravated, which brings potential hazards to the normal operation of buried polyethylene (PE) pipelines. A variety of variables influences the safety of buried pipelines, while the existing research lacks detailed analysis on the issue. A finite element model of buried PE pipeline was developed to analyze how various factors affected the strength of PE pipeline under ground subsidence. Furthermore, the orthogonal test combined with the gray correlation degree was used to analyze the significance of each influencing factor. The results show that (1) the strain rate of the pipe is different at different ground subsidence rates, and the maximum equivalent stress of the pipe increases with the increase of the strain rate; (2) the maximum equivalent stress diminishes with the increasing wall thickness of the pipeline and the length of the transition section; and (3) the factor that has the most significant influence on the maximum equivalent stress of the pipeline is the settlement, followed by the strain rate and the length of the transition section. The internal pressure has the least influence on the maximum equivalent stress in the context of ground subsidence induced stresses.