Long-distance buried pipelines inescapably go through seismic fracture zones which makes the buried pipelines be easily influenced by the diastrophism. A strong and resilient pipe can withstand a certain degree of seismic oscillation. However, it is really difficult for buried pipelines to resist the permanent ground displacement caused by faulting and surface damage. Most of the existing studies only focus on the two-phase contact between pipeline and soil, and the mechanical behavior of the cross-fault pipeline under transportation condition has not been studied. In this article, ADINA finite element software is used to establish a pipe-soil-fluid three-phase coupling model based on fluid–structure interaction (FSI), and the influence of the parameters of pipe, fluid and fault on the mechanical properties of cross-fault buried gas pipeline is studied. The model considering the effect of fluid–structure interaction can effectively simulate the mechanical response of pipelines in the actual working condition. The work presented in this article can provide a reference for the design and safety of cross-fault buried pipeline conveying fluid.

Buried gas pipelines in karst area are inevitably affected by the geotechnical activities, which is difficult to resist the permanent ground displacement caused by soil dislocation and surface damage. In this paper, abaqus finite element software has been used to establish a pipe-soil nonlinear coupling model based on element birth and death technique. The influence rules of various sensitive factors on the stress response of gas pipelines are studied. The work presented in this paper can provide a reference for the design and safety of polyethylene gas pipeline crossing the karst area.

In this paper, the hazard criteria for thermal radiation and shock wave overpressure applicable to the deflagration of urban gas pipelines have been proposed. The phast software is used to analyze the hazard intensity and degree of pipeline deflagration. Based on the hazard criteria, the situation of personnel and object damage is determined, and targeted risk control points are proposed. The influence of the parameters of wind speed, atmospheric stability, air humidity, and operating pressure on the deflagration hazard is studied. The work presented in this paper can provide a reference for the disaster assessment and safety management of urban gas pipelines.