Performance Analysis Of Buried Pipelines Filled With Fluid Crossing Fault

With the rapid development of the national economy, buried pipelines as an important component of modern urban infrastructures have occupied an increasingly important position in modern industrial productions and people's lives. Therefore, it is necessary to research earthquake resistance capability of buried pipelines under the fault. This article mainly research the buried pipeline filled with fluid under the fault, the works as follows:Firstly, many previous theories for the response of buried pipelines crossing fault, reasons and main factors are discussed, then mechanical analysis model to study are proposed: the spring-pipeline-soil model. In order to improve the computational efficiency and ensure the calculation accuracy, soil around the pipelines near the fault used solid models to analysis, the friction between the soil and pipelines were considered; soil around the pipelines far away from fault used spring models to analysis; the interaction between pipelines and soil in both ends of the pipelines used the non-linear equivalent spring to analyze.Secondly, established the pipeline-soil-spring-spring model by finite element analysis software ANSYS, the three-dimensional finite element model of the buried pipeline filled with fluid under the fault was established. Pipelines and fluid respectively adopt shell element SHELL181 and three-dimensional fluid element FLUID30; the interaction between soil and pipeline was modeled respectively by the non-linear equivalent spring element COMBIN39 and three-dimensional solid element SOLID45, and soil modeled by DP materials. In the finite element model, material nonlinearity and geometrical nonlinearity of pipelines and soil, including the interaction of pipelines and soil, pipelines -fluid coupling are considered. Analyzed and compared the impacts of fluid density and fluid pressure on the dynamic response in crossing fault; verified length range of using solid model.Thirdly, through practical calculation examples, fluid density and fluid pressure influencing seismic response are analyzed and compared. The length range of modeled by solid element near the fault is verified under the premise of ensure the calculation accuracy. Using the verified finite element model, some parameters influencing seismic response are analyzed examples. For example diameter, thickness, depth, angle and so on. Some useful conclusions are drawn.Finally, the method of our codes has been introduced. From analysis of result, some advises are proposed.