坑角效应对基坑周边建筑物影响的有限元分析

在基坑工程中，当建筑物紧邻基坑坑角时，坑外土体的不均匀沉降将导致建筑物发生挠曲变形与扭转变形，其中，挠曲变形趋势及挠曲程度取决于建筑物所跨区间内土体沉降曲线的挠曲变形特征，而扭转变形则与建筑物同坑角的相对位置紧密相关．在挠曲变形与扭转变形的共同作用下，建筑物墙体拉应变将受到坑角效应的显著影响．算例结果表明：对于纵墙平行于基坑边的建筑物，当其距坑角距离小于1倍开挖深度时，坑角效应对建筑物变形起不利作用，显著增大了建筑物的墙体拉应变，即此时建筑物是最为不利的；而当建筑物纵墙垂直于基坑边，且距坑角距离小于1倍开挖深度时，坑角效应对建筑物变形起有利作用，使得建筑物的墙体拉应变显著降低；而当建筑物距坑角距离大于1倍开挖深度时，坑角效应对建筑物墙体拉应变的影v向基本可以忽略，但墙体拉应变达到最大值，即此时建筑物是最为不利的．

Finite Element Analysis of Adjacent Building Response to Corner Effect of Excavation

For the building adjacent to the excavation comer, the differential settlement caused by excavation will lead to the deflection deformation and torsion deformation of the building. The trend and degree of deflection depends on the characteristics of ground surface settlement over the cross zone of the building, and torsion deformation is closely related to the relative location between the building and the excavation comer. The impacts of the deflection deformation and torsion deformation on the tensile strain of the building are obviously influenced by comer effect. The results show that when the longitudinal walls of the building are parallel to the retaining wall and the distance between them is smaller than the excavation depth, comer effect has a negative influence on the controlling of deformation of the building. The building is in the most adverse situation in this case. When the longitudinal walls of the building are perpendicular to the retaining wall and the distance between them is smaller than the excavation depth, comer effect has a positive influence on the controlling of deformation of the building, obviously reducing the tensile strain of the wall. When the distance between the building and the comer is larger than the excavation depth, the effect on the deformation of the building can be neglected. However, the building is in the most adverse situation when the tensile strain reaches the maximum value.