Numerical Analysis Of Aseismic Behavior Of Segmental Assembled Bridge Piers Based On Mortise And Tenon Joint

In order to adapt to the rapid development of modern transportation construction,such buildings as viaducts and overpasses gradually began to adopt prefabricated technology for construction.Among them,the seismic performance of segmental assembled pier has been the focus of research by relevant experts and scholars.In this paper,with the combination of the joint technology of shoulder-inserted tenon and mortise structure in the traditional tenon and mortise structure,the bridge pier of tenon and mortise and mortise structure is built,and its seismic performance and damage situation are analyzed and studied.The specific work is as follows:(1)Based on the finite element softwar e of ABAQUS,the modeling process of segmental assembly pier assembly is introduced.It involves the simulation of unbonded prestressed steel bar,the simulation of contact surface,and the simulation method of steel bar and concrete.The feasibility of the modeling method is proved by modeling and analyzing the existing test samples and comparing with the test results.(2)Based on the effectiveness of the modeling method in chapter 2,five kinds of reinforced concrete pier models were established,includ ing RC pier,flat joint pier,mortise and tenon pier,and mortise and tenon pier with no energy-dissipating reinforcement and no unbonded prestressed reinforcement.The results show that compared with RC pier,segway pier has better self-resetting ability and less residual deformation.Compared with the flat joints,the mortise and tenon structure has better bearing capacity,stiffness and energy dissipation capacity.The energy dissipating reinforcement can increase the hysteretic energy dissipation of the pier,but it will increase the residual deformation of the structure.The prestressed steel bar can increase the ductility of the pier and reduce the residual deformation of the pier.(3)Based on the analysis results of the third chapter,taking the ten sile strength of prestressed steel bars,the reinforcement ratio of energy-dissipating steel bars and the strength of concrete as the design parameters,16 segmental composite pier models of mortise and tenon structures were established by using ABAQUS,re spectively.By comparison,it is found that the anti-seismic performance of mortise and mortise pier is the best when the tensile strength of prestressed steel bar is 0.1Af_c,the proportion of energy-dissipating steel bar is 1%and the concrete strength grade is C40.(4)Based on the design parameters in chapter 4,the shape,position and number of tenon and tenon structures are taken as design variables.There are five kinds of segment-based bridge piers,which are arranged in the middl e,rectangular tenon and tenon structures,four rectangular and four trapezoid tenon and tenon structures,and eight trapezoid tenon and tenon structures.Through the analysis of quasi-static reciprocating loading,it is concluded that the residual deforma tion of the segmental assembled pier with trapezoidal mortise and mortise structure arranged in the middle is the smallest,only 5.67mm.Compared with the segment assembly with rectangular mortise and tenon structure arranged in the middle,it reduced by 7 3.3%,making it have stronger self-resetting ability,which is conducive to the post-earthquake repair work.