基坑开挖对邻近不同楼层建筑物影响的有限元分析

Finite Element Analysis of Response of Building with Different Storeys Adjacent to Pit Excavation

在考虑土体小应变刚度行为的基础上,对基坑邻近不同楼层建筑物的变形进行精细化分析.分析结果表明:当建筑物跨越坑外沉降槽最低点时,建筑物将发生下凹挠曲变形,此时建筑物的挠曲值及墙体拉应变均随着楼层的增加而减小,而当楼层大于4层时,建筑物的挠曲变形与墙体拉应变则不再随楼层的增加而减小,即此时楼层低的建筑物最为不利;当建筑物跨越坑外沉降槽的上凸区域时,建筑物将发生上凸挠曲变形,且挠曲变形导致楼层为3层的建筑物墙体拉应变最大,即3层的建筑物最为不利.故当基坑周边存在楼层数不同的建筑物时,应对建筑物最为不利的楼层数进行判定,从而加以针对性保护.

Considering the small strain stiffness behavior of soil,the response of the building with different storeys adjacent to excavation was analyzed in detail.The results show that when the building locates over the lowest point of the settlement trough,concave deflection occurs.Both the degree of deflection and the tensile strain of the wall decrease with the increase of the building height.But when the number of building storeys is greater than 4,the deflection and the tensile strain remain constant.In this case,the lowest building is in the most adverse situation.When the building locates over the hogging zone of the settlement trough,convex deflection occurs.In this case,the tensile strain of 3-storey building reaches the maximum value and the 3-storey building is in the most adversity.Therefore,for the buildings with different storeys adjacent to excavation,it is necessory to predicate the most negative number of storeys for targeted protection.