ABSTRACT
Earthquake damage investigations show that thrust faults often bring serious damage to gas pipelines, and easily cause secondary disasters such as fire and explosion. As a thin-walled shell structure, the gas supply pipeline is vulnerable to large compression deformation caused by thrust fault movement. This article studies the seismic safety of the gas pipeline crossing the Kezil thrust fault, taking the Dabei gas pipeline as an example. Through the field trench excavation of the Kezil fault, the fault plane inclination angle, the fortified fault displacement and the site soil characteristic parameters are determined. The shell finite element model has been adopted to analyze the large deformation of the gas pipeline under this thrust fault displacement, and the results are compared with the pipe’s allowable tensile strain and compression strain. Finite element method results show that the main deformation of the pipe under thrust fault movement is the compression strain, and the amplitude of compression strain can be reduced with a decrease in the crossing angle. When the crossing is less than 11°, the pipe’s maximum axial compression strain and tensile strain caused by the Kezil fault could be within the allowable strain range according to the requirements of seismic design code.
