Shoal Buried Gas Pipeline Anti-floating Calculation And Experimental Study

Shoal pipeline is an a key link that make the petroleum and gas from the ocean transport to the land, and it’s widely used now. To ensure the safety of the petroleum and gas transportation process and reduce the transportation cost, confirming the environmental load that pipeline beared is very important for the calculation analysis of pipelines’ strength, deformation and anti-floating. Under the hydrostatic pressure, shoal gas pipeline may be confront the“drift tube” problems due to the influence of water buoyancy. At present, the numerical calculation methods were mainly adopted to analyze the pipe floating resistance, despite its optimal calculation method. But the relevant theoretical information is not comprehensive enough, that result in the boundary conditions are difficult to determine. Therefore, in this paper, the shoal buried gas pipeline stress,deformation law and floating resistance problem were studied. Referencing the tunnel minimum rock cover thickness and the theory of minimum thickness of overlying soil,obtaining the corresponding pipe minimum depth calculation theory. Through the anti-floating calculation theory of the pipes, the mechanics model that used in calculate the floating resistance of the shoal pipeline is established, the critical condition of the pipeline floating that under the different friction angle and cohesion is presented, that is the critical value of the minimum depth of the pipes. Using the improved calculation method of the pipes’ minimum depth, then calculating and analyzing the three shoal areas of caofeidian. At last, a series of the critical value of the Minimum depth of the pipes are obtained. Establishing the 3-D pipe finite element optimize model,calculating and analysing the pipeline anti-floating problem by the method of numerical. It is concluded that the proportionality coefficient should considered when the theoretical method calculating the soil initial fracture. For study the shoal buried gas pipeline’s deformation and stress law that under a certain depth.The buried pipes physical experiment platform is structured in this study, and has designed and conducted the shoal buried gas pipeline deformation similar test, simulating shoal pipeline deformation process that under a predetermined conditions. The corresponding finite element calculation model is established. then, compared the experimental resultfinite with finite element numerical calculation results, obtained the stress and deformation law of the pipeline that under a certain depth, it can giving some references for the pipeline engineering construction.