基于黏弹性边界的渡槽结构地震动力特性分析

Study on Ground Motion Failure Mechanism of Aqueduct Structure Based on Viscoelastic Boundary

建立了双洎河渡槽地震动分析的数值仿真模型,编制程序实现了黏弹性人工边界法,并通过算例验证其正确性,黏弹性边界具有良好的波动能量吸收和耗散效果。考虑水体动力效应,基于黏弹性边界,进行渡槽结构地震动力特性分析。对渡槽结构的动位移和动应力分析表明:随着渡槽结构高度的增大,结构响应的加速度有增大趋势;支墩底部到槽身顶部,水平向加速度对结构的影响更加明显;槽身底板与支座相交处和支墩底部的动应力值水平较高,是地震动薄弱的集中区域,需加强局部配筋或支撑以增强抗震能力。

A numerical simulation model for seismic analysis of Shuangjihe aqueduct was established, and the viscoelastic artificial boundary method was realized by programming. The validity of the method was verified by an example. The developed viscoelastic boundary had good wave energy absorption and dissipation effect. Considering the dynamic effect of water body, The seismic dynamic characteristics of aqueduct structure were analyzed based on viscoelastic boundary. The research results of dynamic displacement and stress of aqueduct structure show that with the increase of the height of aqueduct structure, the acceleration of structural response tends is increased;from the bottom of pier to the top of the aqueduct body, the influence of horizontal acceleration to the structure is more obvious;at the intersection of the bottom of the aqueduct body and the support, and at the bottom of the pier, the dynamic stress level is higher. Local reinforcement or bracing should be strengthened to increase seismic resistance in concentrated areas with weak ground motions.