Finite Element Analysis Of The Buried Piping Elbow Near The Fixed Pier Suffered Thrust

When the buried transmission piping is built, the major temperature difference of piping when being placed and when working makes it necessary to lay a fixed anchorage so as to limit the expanding displacement.The key point designing a fixed anchorage is to determine its pushing force. In this article, two ways are comprehensively reviewed on calculating the forces. The theoretical formula, though having analyzed all the forces no the anchorage, is unfit for engineering; while the actual formula being used in engineering is based on a rough model, which differs a lot from the reality.Here, author applies Finite Element Method (FEM) to analyze all the forces on the fixed anchorage near the buried piping's elbow and to simulate with unlinear springs the soil's effects on piping and fixed anchorages to build a mechanic model about piping-soil-fixed anchorages interaction. By calculating the axial internal forces of piping with different elbow's included angles, elbow's curvature radius and soil parameters, author concludes that the difference between the buried piping and other technological piping lies in the elastic support by soil. When analyzing the forces on the buried piping and the fixed anchorages, the soil's effect has to be considered. After analyzing the calculating results, can say the FEM models are close to the reality.When comparing the pushing forces under different piping diameters and temperature condition, the reasonableness in the former projects is remained, the quadratic curves between actual pushing's and experiential pushing's on anchorages are fit and the amendments of the former formula are offered, which can give many references to the designers.