Research On Aseismic Behavior Of Continuous Beam Bridge Structure Using Variable Curvature Friction Pendulum Bearing With Speed Lock-up Device

Variable curvature friction pendulum bearing with lock-up is a kind of seismic isolation device has wide application prospect.The lock-up device(LUD)has been installed on the variable curvature friction pendulum bearing to control the different working modes of bearing under normal and seismic conditions at different levels.The study of its aseismic performanc and application are carried out using finite element analysis and shaking table test,and the main results in this paper are as follows:Three kinds of bridge type with different span are selected to establish analysis model,the nonlinear time history method is applied to analyze the seismic response of the analysis model under 4 different site types and 7 kinds of seismic waves.The applicability of variable curvature friction pendulum bearing with lock-up is evaluated by finite element method.The lock-up device with different numbers is set up for three analysis models,and the seismic effect under different site types is analyzed.Under earthquake action of E1 stage,the bearing can reduce the seismic force,and the reduction rate of seismic force is related to the natural vibration period of bridge structure.Under earthquake action of E2 stage,the bearing can apparently reduce the seismic load of a single pier and the displacement of beam.Solid model of variable curvature friction pendulum bearing with lock-up is established to analyze its hysteretic behavior.The shear force of bearing shear pin is calculated,and the ratio of lateral horizontal force to longitudinal seismic force is basically between 1.1 and 1.8.The shear force of shear pin is determined by transverse seismic force.The larger the diameter of the damping ball pendulum,the smaller the yield stiffness and effective stiffness of the skeleton curve.Scale test of continuous beam bridge(3×30m)of with equal section is done by shaking table.The experiment results show that: the bearing can make the acceleration response of the bridge structure increase slightly,the displacement response decrease,and shear force of the pier significantly reduce.The bearing can effectively make every pier work together to resist earthquakes,reducing shear force of the fixed pier.The variable curvature friction pendulum bearing with speed lock-up has been applied in the Jinhan highway viaduct(Hancai road to Haibin highway)G20~G23.The damping effect of the bridge by setting the bearing is analyzed,and the economical efficiency is also evaluated.