Nonlinear Finite Element Analysis And Optimization Design Of Reinforced Concrete Inverted Siphon Based On ANSYS

As a widely used cross engineering and important concealed engineering,inverted siphon is known as lifeline engineering in the world.There are complex interactions between the stress and deformation of the structure and the outline dimension,filling thickness,filling property and the initial boundary conditions.In addition to meeting the normal water delivery,reasonable design of the structure is also necessary.So it is particularly important to analyze and calculate the structure of the inverted siphon and the surrounding soil reasonably and make optimal design on the structure to ensure the stability,safety and economy property of the whole structure system.Based on numerical simulation method,the inverted siphon engineering across the West Taipingchuan Channel in the northern irrigated area of the main channel of the Yi'an Farm in Heilongjiang Province was taken as the research object in this paper.The finite element analysis software ANSYS was applied.Firstly,in view of five working conditions encountered in engineering operation,the integral model of reinforced concrete was adopted,three dimensional entity model of pipe body and surrounding soil under the original design scheme was built,and the stress and deformation of pipe body and surrounding soil were analyzed respectively.Secondly,combined with the stress value of the pipe body,the original inverted siphon section and reinforcement were optimized,and simulation analysis under two worse operating conditions were carried out on the optimized inverted siphon body.The reliability of the optimized design scheme was verified,the quantity and cost of the project were compared and the economical efficiency was analyzed.The paper's main research contents and conclusions are shown as follows:(1)The basic principle and analysis steps of finite element and the solution procedure were introduced.The constitutive relations and the failure criterion of the three kinds of materials—concrete,reinforcement and soil were summarized,and the processing way of reinforcing steel bar in finite element analysis of reinforced concrete was also summarized.(2)According to the results of finite element analysis in the original design scheme,it was found that the tensile and compressive stress of the pipe body concrete were far from the design value and had large surplus in the five operating conditions.The worse operating conditions occurred in completion period without water in the pipe and the overhaul period of inverted siphon.(3)According to the finite element analysis results of the soil around the pipe body in the original design scheme,it was found that the soil body was stable in different operating conditions,and the maximum settlement was 16.2 mm and on the free surface of the backfill on both sides of the body.The overall settlement of the pipe body was average,the maximum amount of sediment was about 10.3 mm,which met the design requirements for the settlement of inverted siphon.The maximum compressive stress of pipe soil was 114 k Pa and the ground bearing capacity was good,which basically met the design requirements of the foundation bearing capacity of the project.(4)Combined with the hole stress value obtained by ANSYS numerical simulation,the original reinforced concrete inverted siphon structure was optimal designed.According to the results of finite element analysis after optimization,it can be seen that the optimized inverted siphon structure was safe.Through the comparison of the project cost,it was found that the optimized design scheme can greatly reduce the cost.