Study On Calculation Of External Pressure Resistance And Reinforcement Design Of Stiffening Ring Buried Steel Pipe In Shizhu Hydropower Station In Chongqing

In the water conservancy project,the pressure pipeline is an important water conveyance building,which needs to be designed safely and economically.With the development of science and technology,the types and layout forms of pressure pipes become more and more numerous,and the structural analysis methods become more and more complex.Therefore,the most appropriate calculation method should be selected for different pipe forms and external influencing factors.In this paper,based on an engineering example and focusing on the practical problems of buried steel pipe reinforcement against external pressure,the structure of pressure pipe used in a hydropower station is first introduced,and the preliminary parameters of the pressure pipe are designed by using the traditional algorithm,so as to provide a basis for the subsequent optimization calculation formula.Then on the basis of the hydropower station pressure pipe specification,in combination with different pressure steel pipe formula for calculating the stability under external pressure,the stiffening ring resistance to external pressure calculation methods of buried steel pipe is optimized,and the optimized calculating formula for reference,the effect factors of the reinforcement effect of external pressure stability were analyzed,find out the key influencing factors:diameter-thick ratio comprehensive,stiffening ring spacing,soil modulus of deformation,etc.Then in different reinforcement scheme,the pipeline between two stiffening rings as the research object,the pressure pipe wall thickness,stiffening ring spacing calculation as optimization variables,such as the stiffening ring together with the steel tube does not lose stability under external loads as a constraint condition,by using the optimized against external pressure bearing capacity calculation formula for the safe and economical analysis of different reinforcement scheme.Finally,the three-dimensional model of stiffening ring type buried steel pipe is established by using finite element ANSYS software,and the characteristic value buckling analysis and nonlinear buckling analysis are carried out for different reinforcement schemes,and the results are compared with the calculation results of the formula.Through comparison,it is found that the reinforcement effect proposed by the new calculation method is basically consistent with the result obtained by the finite element simulation.In this paper,the optimized calculation method of stiffening ring type buried steel pipe is proposed,which can maintain the structural performance while meeting the external load and achieve the purpose of more material saving.The methods and results in this paper can provide some references for the similar stiffening ring type buried steel pipe to design its stability against external pressure in the future.