预制混凝土拱涵地震响应分析

Analysis on Seismic Responses of Precast Concrete Arch Culvert

首先建立拱涵二维有限差分模型,对拱涵的安装与路堤的填筑过程进行模拟,并得到拱涵与填土体系受力的初始状态;然后对拱涵进行时程分析,探究拱涵在地震作用下的位移与应力响应规律;最后着重论述填土高度、地震加速度以及地震波传播角度对拱涵地震动力响应的影响,并分析混凝土预制拱涵在地震作用下的薄弱位置。结果表明:随着填土高度的增加,拱顶与基底之间水平相对位移逐渐增大,拱涵各个接触面的内力在静态内力的基础上显著非线性增大;拱涵的各个接触面的内力对峰值加速度的改变较敏感;随着地震波传播角度的增大,拱顶与基底水平相对位移将减小,拱涵的内力响应也逐渐减小。

A two-dimensional finite difference model is firstly established,and the process of installation of the precast arch culvert is simulated to obtain the initial state of arch culvert.Time history analysis is then performed to find the response laws of displacement and stress resultants of culvert structures.Finally,a wide range of parametric studies are carried out to investigate the influence of height of fill,peak ground acceleration and the propagation angle of seismic wave on the responses of arch culverts under seismic loads.Another important task is to find out the most vulnerable components or interfaces of the whole precast culvert.The results show that the lateral relative displacement between the arch crown and the foundation base,and the peak values of internal forces under seismic loads increase considerably and nonlinearly as the height of fill increases.The peak values of internal forces are sensitive to the minor variations of peak ground acceleration.Both the lateral relative displacement between the arch crown and the foundation base and the responses of stress resultants of culvert structure decrease when the propagation angle of seismic wave increases.