Analysis Method Of The Response Of Buried Pipelines Crossing Fault To The Fault Rupture

The research of the response of buried pipeline crossing fault is very significant in lifeline earthquake engineering. In the first chapter, the studies of buried pipelines crossing faults, including the researches of theory and experimentation, and parameters, are introduced at first. Theoretic research and experimentation research, along with the relations among various researches, are introduced in their order of development, and the relative parameter research of different materials is described in turn. The influence of the main parameters on the strain response of a buried pipeline crossing the fault, and the significance of seismic design about the parameters, are concluded. Also, the urgent problems of buried pipeline are analyzed according to the damage characteristic and the design requirement of the pipeline.The previous studies show that as for the studies on the best crossing angle between pipeline and fault, the basic assumptions of existing approaches are the pipelines fail in tension crack of pipe for studies on the best crossing angle between pipeline and fault, but these approaches do not consider the cases of pipeline failures induced by the compression crack or buckling of the pipe. In the second paper, some case studies are made by the finite element method with shell model of pipe. In which the different material behaviors of pipe, dimensions of pipe and properties of surrounding soils are taken into consideration. Based on the results of case studies, the failure problems of pipelines are discussed under different rules of failure control of pipes which are the rules of only controlling the tension failure of pipe or controlling both the tension failure and the compression failure of pipe, and the influences of the different rules of failure controlling are analyzed on the best crossing angle between pipeline and fault. The results are obtained that the rule of failure control is an important factor to bring out the best crossing angle between pipeline and fault, and the best crossing angle should be about 70 degree under the rules of controlling both the tension failure and the compression failure of the pipe, So it is suggested that with the crossing angle less than 70°, the tension strain of pipes should be used to analyze the response of buried pipeline, and that with the angle between 70° and 90°, compression strain of pipes should be used.