RESEARCH ON ASEISMATIC MEASURES OF GAS PIPELINE CROSSING A FAULT FOR STRAIN-BASED DESIGN

There are a lot of researches on qualitative aseismatic measures for buried gas pipeline crossing movable faults. But a few of them are quantitative, especially in the size and shape of the trench. In this paper, based on strain-based pipeline design method and finite element method, a new strain analysis model for buried large diameter gas pipeline is presented that deals quantitatively with the pipeline strain influencing factors, such as the size and shape of the trench, buried pipe depth, crossing angle between pipeline and fault, pipe diameter and wall thickness, mechanical properties of original soil and back fill soil, inner pipeline pressure. In this model, the pipeline is simulated by pipe element and elbow element, soil-pipe interaction is reduced to 3 dimensional soil spring. By means of FEM software ABAQUS, detail analysis is performed for a real design case of pipeline crossing a movable fault in the second west-east gas pipeline project of China, and optimized pipeline crossing fault scheme is proposed which can minimize the pipeline strain and limit it in allowable value.