Failure Classification Study of X70 Pipeline Crossing Earthquake Fault Based on Shell-Contact Model

Shell-contact theory model is studied in order to analyze axial compressive strain of X70 pipeline crossing faults on the condition of coupling between pipeline and soil, and pipeline failure classification method is proposed based on axial compressive strain. According to the magnitude of pipeline axial compressive strain, four grades of A,B,C,D are divided for pipeline failure degree, and pipeline failure classification standard is determined. Using the classification method and standard, some factors influence regulation of X70 pipeline failure degree are analyzed, such as pipeline wall thickness, buried depth, cracked zone width, slip amount, intersection angle. Pipeline damage location and distribution scale are compared under the condition of the different parameters variation, and sensitivity of the influence factors is summarized. The results indicate that X70 pipeline failure degree decreases with the increase of fault fracture zone width; the pipeline failure degree is more strenuous on the different soil conditions of fault both sides.