考虑河谷场地效应的大跨度拱桥的地震响应分析

Analysis on Seismic Response of Long-span Arch Bridge Considering River Valley Site Effect

摘要:

为研究V型河谷场地效应对大跨度钢管混凝土拱桥的地震响应影响，以某大跨度钢管混凝土拱桥为工程背景并简化V型河谷场地模型，建立河谷-拱桥有限元模型，讨论在SV波作用下对桥梁的地震响应影响。结果表明：由于地震荷载是均匀作用在场地，且河谷-拱桥有限元模型是轴对称模型，因此得到的拱桥主拱圈的内力和位移响应趋势是对称分布；不同地震波作用下得到的主拱圈内力和位移响应大小不同，这和拱桥拱脚与场地连接部位的地震动强度和地震波的频谱特性有关；在进行桥梁抗震设计时，SV波作用下拱桥关键部位应重点关注。

Abstract:

In order to study the influence of V-shaped river valley site effect on the seismic response of long-span concrete-filled steel tube arch bridge, taking a long-span concrete-filled steel tube arch bridge as the engineering background, the V-shaped river valley site model is simplified. The overall finite element model of river valley - arch bridge is established to discuss the seismic response effect on the bridge under SV wave. The results show that the internal force and displacement response trend of the main arch ring of the arch bridge are symmetrically distributed because the seismic load is uniformly acting on the site and the river valley - arch bridge model is an axisymmetric model. The internal force and displacement response of the main arch ring under different seismic waves are different, which are related to the ground motion intensity at the arch foot and the site connection part of arch bridge, and related to the spectral characteristics of the seismic wave. In the seismic design of bridge, the key parts of arch bridge under SV wave should be focused on.