Research And Verification Of Optimal Design Of Pressure Buried Pipe Structure With Stiffening Ring

In the water conservancy project,the pressure pipeline is an important water conveyance building,which directly relates to whether the entire hydropower station can realize the function of normal power generation.The design of pressure pipes is often limited by factors such as geography,meteorology and man-made.It is often necessary to use buried pressure pipes with more flexible layout.The structural form and stress conditions of buried pressure pipes with stiffening rings are complex,and traditional designs often fail to fully optimize the structure,while at the same time failing to balance safety and economy.Through the optimized design of the buried pressure pipeline,the structural size is optimized,and under the premise of ensuring safety,the amount of material is used less and the economy is more economical.Therefore,it is necessary to optimize the structural design of buried pressure pipes with stiffening rings.This paper first introduces the traditional algorithm of structural design of pressure buried pipe,and uses the traditional algorithm to carry out preliminary design of buried pressure pipeline with stiffening ring of a hydropower station,providing comparison and reference for optimization design.Then based on the preliminary design scheme of the hydropower station,an optimal design scheme based on the structural reliability index is established.In the optimization design,the pipeline between the two stiffening rings is taken as the research object;the thickness of the pressure pipe wall,the inner radius of the pipe,the spacing of the stiffening ring,the thickness and height of the stiffening ring are taken as optimization variables;the pipe between the two stiffeners The volume is used as the objective function;the constraint condition is that the steel pipe and the surrounding rock together withstand the internal water pressure and the stiffening ring steel tube can withstand the external water pressure and can operate normally.In this paper,the reliability index is calculated by using the checkpoint method.The complex method is used to optimize the overall structure,and the two schemes are compared for safety and economy.The entire optimization process is implemented by programming with MATLAB software.Finally,the finite element ANSYS software is used to establish a three-dimensional model of the buried pressure pipeline with stiffening ring.Under the internal water pressure,the stress analysis and the displacement analysis are performed on the initial design scheme and the optimized design scheme.Under the external water pressure,the eigenvalue buckling analysis and the nonlinear buckling analysis are performed on the initial designscheme and the optimized design scheme.By comparison,it is found that the optimized design of the buried pressure pipeline with stiffening ring can achieve more material saving in the case of meeting the structural reliability requirements and maintaining the structural performance balance under pressure.The size of the optimized design is 10% smaller than the initial design.In addition,the optimized design method has the characteristics of simple and reliable design,and can find the global optimal solution in a short time.The methods and results of this paper can provide some reference for the design of buried pressure pipelines with stiffening rings.