四主缆大跨悬索桥抗震性能分析及减震措施优化OA北大核心CSTPCD

Taking Yanji Yangtze River Bridge(YJB)as the engineering background,firstly,the seismic performance of YJB is analyzed using the dynamic nonlinear time history method.Moreover,the effects of installing the eddy current-friction combined damper(EC-FCD)and viscous damper(VD)on the seismic performance of the long-span suspension bridge are studied.Furthermore,the parameter sensitivity analysis of the friction force,damping coefficient and damping index of the EC-FCD is carried out,respectively.Finally,from the perspective of energy dissipation,the characteristics of the EC-FCD on the large-span suspension bridge under earthquake are analyzed.The results show that under the E2 earthquakes,the resistance bending moment of key sections of the pylons is greater than the demand bending moment,and the longitudinal displacement of the stiffened girder end is relatively large under the longitudinal and vertical earthquakes.The longitudinal displacement of the stiffened girder end can be effectively reduced by installing longitudinal dampers at the interaction of pylon and girder.Moreover,increasing friction and damping coefficient,as well as decreasing damping index can improve the control effect of longitudinal displacement at the stiffened girder end.However,changing these parameters has little effect on the seismic response of the key sections of the pylons.When the damping coefficient is large,eddy current damping dominates the energy dissipation of the EC-FCD.Compared with the VD,the EC-FCD has a better control effect on the longitudinal displacements of the stiffened girder ends.