黏滞阻尼作用下高墩大跨度连续刚构-拱组合桥减震效果分析

Analysis of Seismic Reduction Effect of Long Span Continuous Rigid Frame Arch Composite Bridge with High Piers Under Viscous Damping

以西安至延安高速铁路大跨度箱形截面(124+248+124)m连续刚构-拱组合桥为研究对象,利用MIDAS/Civil有限元软件建立三维模型,通过非线性时程分析法研究在连续刚构-拱组合桥边墩设置黏滞液体阻尼器后桥墩内力及主梁位移的变化情况,在此基础上对阻尼器参数进行优化,探究黏滞阻尼器减震效果最佳时的参数组合。结果表明:设置黏滞液体阻尼器后,随着阻尼系数增大,西安侧桥墩的墩底弯矩单调递减,墩底剪力先减小后增大,延安侧桥墩的墩底弯矩和剪力均先减小后增大;随着阻尼系数增大,主梁位移逐渐减小,减震效果逐渐增强。综合考虑墩底内力及主梁位移,阻尼系数为4 MN·(s/m)^(0.4)时减震效果最佳。

Taking the long span box section(124+248+124)m continuous rigid frame arch composite bridge of Xi’an-Yan’an high speed railway as the research object,a three-dimensional model was established by using MIDAS/Civil finite element software,and the changes of pier internal force and main girder displacement after setting viscous liquid damper on the side pier of continuous rigid frame arch composite bridge were studied by nonlinear time history analysis method.On this basis,the damper parameters were optimized to explore the best seismic reduction effect of viscous damper parameter combination.The results show that after setting viscous liquid damper,with the increase of damping coefficient,the bending moment at the bottom of Xi’an side pier decreases monotonously,the shear force at the bottom of pier decreases first and then increases,and the bending moment and shear force at the bottom of Yan’an side pier both decrease first and then increases.With the increase of damping coefficient,the displacement of main girder decreases gradually,and the seismic reduction effect increases gradually.Considering the internal force of the pier bottom and the displacement of the main girder comprehensively,the damping coefficient of 4 MN·(s/m)^(0.4)is the best.