地裂缝场地地铁运行引起框架结构振动的数值分析

摘要

Focusing on the vibration problem of buildings induced by Xi’an metro operation in ground fissure area, a three-dimensional finite element model including tunnel, ground-fissure and frame-structure is established. Model analysis and vibration response analysis of the buildings are conducted. The results are compared with those of the same model under the same loading condition but the ground fissure effect is not considered. It is indicated that the structure’s vertical vibration is stronger than the horizontal one; the ground fissure has little effect on the distributions of horizontal and veridical vibration accelerations. The former shows a fluctuating distribution with the floor rising, while the latter only shows insignificant difference of all the floors except the first floor. The ground fissure has large influence on the distribution of the vertical acceleration. It increases with the floor rising in the non-ground fissure area, while in ground fissure area, it decreases initially and increases later with the floor rising. The ground fissure causes the increasing of frame’s vertical vibration acceleration, both vertical and horizontal vibration acceleration increases in some floors.%针对西安地裂缝场地地铁运行引起地面建筑物的振动问题，建立隧道-地裂缝-地层-框架结构三维有限元模型，进行建筑物的模态分析和振动响应分析，并与同荷载工况的无地裂缝场地框架结构的振动响应进行对比。结果表明：结构的竖向振动比水平向强烈；地裂缝对结构横向和竖向振动加速度的分布影响不大，前者随层高呈波动性分布，后者除首层之外，其余各层差异不大；地裂缝对纵向振动加速度的分布规律影响较大，无地裂缝时呈逐层增加的分布，有地裂缝时呈两端大中间小的分布；地裂缝使结构竖向振动加速度有增大趋势，横向和纵向加速度会在局部楼层增大。