Study On Seismic Isolation Of Simple Supported Beam Bridge Based On The Same Spherical Direction Double Spherical Surface Seismic Mitigation And Isolation Bearing

In recent years,China's high-speed railway has achieved great leap forward development.Meanwhile,with the frequent earthquakes in central and western China,the seismic performance of high-speed railway bridges is becoming more and more important.However,due to the difficulty of ductile seismic design for high-speed railway,seismic isolation and aseismic system has become an ideal concept of seismic design for high-speed railway.In this paper,the aseismic performance of the same spherical direction double spherical surface seismic mitigation and isolation bearing is applied to the simple supported beam bridge of high speed railway.The main research contents are as follows:?1?After reading a lot of literatures,present research situation of principle and technology of seismic isolation and aseismic system and the application status of some seismic isolation and aseismic devices have been investigated in detail.?2?By using the ANSYS finite element analysis software,the solid models of the shock absorbers were established,and the distribution of stress and strain under horizontal force of the shock absorber top was given,and the force-displacement curves of the shock absorbers were obtained under the action of the horizontal force of the shock absorber top.?3?Based on the flat section assumption,considering of material nonlinearity,the theoretical calculation method and the calculation flow chart of the relationship under the action of horizontal force of the shock absorber top were given.The theoretical calculation results of relation between force and displacement were in agreement with the calculation results of the ANSYS solid model.?4?Based on the MATLAB programming software,the influence of shock absorber shape parameters d₀,L₁ and L on the mechanical properties of damping tenon were comprehensively analyzed based on the computer program.?5?In view of the bearing seismic dowel,the principles and one of calculation method of shearing force of seismic dowel were discussed,and the changing laws of shear force with the height of the pier and the condition of site were given.?6?In order to explore the seismic isolation and aseismic effect of the simple beam bridge with the same spherical direction double spherical surface seismic mitigation and isolation bearing,the numerical simulation method of the seismic isolation and aseismic fixed support and movable bearings were first given,and the time history results of three simple supported beam bridges with different support arrangement were carried out,and the results were compared and analyzed.The results show that the relative displacement between pier and beam can be more effectively reduced by adopting the movable same spherical direction double spherical surface seismic mitigation and isolation bearings with shock absorber.?7?Finally,the full bridge models of the simple supported beam bridge were established and the effect of the initial shift clearance of movable bearings,the height of the pier and the friction coefficient on the seismic isolation performance were analyzed by the time history analysis method.