近断层地震作用下大跨连续梁桥拉索减震支座数值模型研究

Seismic Damping Control of Long-Span Base-Isolated Continuous Beam Bridge Under the Action of Near-Fault Ground Motion

为研究近场速度脉冲型地震动作用下不同参数的拉索减震支座的减震性能,以一座三跨连续梁桥为研究对象,基于MIDAS/Civil平台建立有限元模型。采用非线性时程分析方法计算该桥在不同拉索减震支座参数组合下的减震效果,研究支座参数对减震效果的影响。结果表明,随着脉冲周期的增大,拉索减震支座对桥梁的墩梁相对位移减震率逐渐增大,拉索减震支座具有良好的限位能力,可有效防止桥梁碰撞、落梁等灾害。为实现拉索减震支座的减震性能最优化,拉索支座的初始间隙需控制在0~0.10 m。

In order to study the seismic damping performance of the cable sliding friction aseismic bearings with different parameters under the near-field velocity pulsed ground motion,a three-span continuous beam bridge is taken as an example,and a finite element model of this bridge was established by MIDAS/Civil.The nonlinear time-history analysis method was used to calculate the seismic damping effect of cable sliding friction aseismic bearings under different parameter combinations,and the influences of the bearing parameters on the seismic damping effect were studied.The results show that the displacement damping ratio of the cable sliding friction aseismic bearing of the bridge gradually increases with the increase of the pulse period.Moreover,it has a good ability to limit displacement,which can effectively prevent bridge collisions,beam droppings and other disasters.To achieve the optimization of the seismic damping performance of the cable sliding friction aseismic bearings,the initial gap of cable bearings should be controlled within 0~0.10 m.