Stress Characteristics And Offloading Analysis Of The Municipal Buried Pipelines Under Load

With the frequent occurrence of natural disasters, the safety of buried pipeline as an important lifeline ways come out gradually, energy transport pipeline is the most economical and reliable way, the importance in city construction is particular. Pipes are buried in the soil, bounded by the surrounding soil medium, force characteristics is largely limited. However, the length of the pipeline make it a linear structure, crossing condition is complex, therefore analysis the stress and strain of the city buried pipelines is imperative, so does the damage mitigation.The force characteristics of cast iron water pipes is typical, many researchers have conducted a number of studies of buried pipelines which covers longitudinal and transverse mechanical properties. This paper bases on the basis of previous studies, using finite element analysis software ANSYS build different diameters nonlinear friction model of cast iron water pipes, which aims to establish a more reasonable pipeline analog form, to get more reliable results, so that to analysis the failure and reliability of the pipeline under different loads. Specifically, the main research work carried out in this article include:(1) Without considering the uneven ground subsidence, the key parameters of the Pipeline Analysis model are given to build vertical soil pipe coupling model for pipeline internal force analysis, and calculate the horizontal, vertical, hoop stress of pipes.(2) The piping failure and reliability analysis proposes pipeline failure criterion and the determining steps of failure, to propose the carrying capacity of the pipeline structure hydrochloric dangerous point, and reliable indicators and failure probability of pipeline structures.(3) Using finite element analysis software ANSYS build finite element contact model of pipe-soil, analyze the pipe stress, strain, and displacement of different parameters of the pipeline quantitatively, and analyze the impact of parameters on the pipe, analyze the pipe stress distribution characteristics of different conditions, determining its failed states.(4) On the basis of the calculation and simulation, buried pipeline stress distribution characteristics is descripted, and according to engineering practices, proposing reasonable design and optimization of load reduction measures and analyzing its feasibility.