排架支撑式渡槽排架损伤下地震响应分析

以洗耳河渡槽为例,以弹塑性梁单元模拟排架,采用有限体积法、ALE及二阶迎风格式模拟槽内水体,建立了二维槽—水耦合体,分析了横向地震作用下的排架损伤下渡槽动力非线性响应,并与线弹性梁单元模拟排架的分析结果进行对比。结果表明,在所选地震波横向作用下,排架发生损伤造成了刚度下降、结构振动周期延长,从而逼近水体的一阶晃动周期,引起了槽—水耦合体内水体的大幅晃动;排架损伤后槽底水平位移增大而水平加速度减小,槽内水体作用于槽体底部的动水压力、倾覆力矩、倾覆力减小。

Seismic Analysis of Dynamic Response of Flume with Damaged Framed Bent

Taking Xier River flume for an example, the transverse seismic nonlinear response analysis of flume with damaged bent is carried out by using the numerical model. The bent is simulated by elastic plasticity beam element and the water in two-dimensional duct-water coupled components is modeled by finite volume method, ALE and second-order upwind scheme. By comparison of results from numerical model in which the bent is simulated by elastic beam element, two conclusions are obtained. The first is that the seismic damage of bent can lead to stiffness reduction of bent frame column and natural period elongation of flume. Both of them cause large amplitude sloshing in duct because the extended natural period of flume approaches to the first-order period of water sloshing. The second is the seismic damage of bent results in the increase of horizontal displacement, reduction of the horizontal acceleration of the duct and the reduction of hydrodynamic pressure, overturning moment and overturning force at the bottom of duct wall.