Study On Special Seismic Response For Long-span Suspension Bridge Under The Long-period Ground Motion

Under the effect of long-period ground motion, the flexible long-span structure are easily damaged, this paper based on the long-span suspension bridge as the engineering project, considering the long-period ground motion characteristics, multiple-support excitation, the effect of wave passage, special seismic response for long-span suspension Bridges is studied, In this paper, main work is as follows:.(1) According to long-period ground motion spectrum feature selection criteria, select 45 of four site conditions long-period ground motion records from the Japanese K-NET, Ki K-net strong earthquake database, contrast the elastic response spectrum between the long-period ground motion and the ordinary earthquake, from two aspects of the ground motion characteristics and structural dynamic model parameters, the influence of the parameters on the elastic-plastic response spectrum of long period ground motion is analyzed, from the perspective of engineering seismic,deeply researching the long-period ground motion spectrum feature.(2)Based on the Puli bridge and Nizhou bridge of two different span of long-span suspension bridge as the engineering example, considering the long-period seismic characteristics and the effect of wave passage, adopt the consistent excitation method, the large mass method and the displacement method for seismic response analysis of long-span suspension bridges, and studied the difference between the results of the three methods and find the reasons, analyzed the coupling effects of the long period ground motion and the wave passage effect on the seismic response of the long-span suspension bridge.(3) The Puli bridge as the example, choose the viscous damper as the shock absorption measures, analyse the seismic response of the long-span suspension Bridges with the viscous damper under long-period ground motion considering wave passage effect, and study the influence of the long-period seismic characteristics and the wave passage effect on the shock absorption effect of viscous damper, contrast the damping effects of viscous damper under long period ground motion and the ordinary earthquake.To sum up, in this paper, the special seismic response of long-span suspension Bridges under the long period ground motion are studied, some useful conclusions are obtained, and can provide reference for seismic design of similar engineering.