采煤沉陷区大型建筑物与地基相互作用机理研究

Study on interaction mechanism between large buildings and ground in coal mining subsidence area

井下大规模开采将导致覆岩移动、变形乃至破坏,并在地表形成大范围的沉陷区,形成不良地基,存在再次沉陷变形的可能,在沉陷区上兴建大型建筑物将存在着较大的安全隐患,认识建筑物与地基相互作用机理是确保建筑安全的前提。以大型建筑物结构为研究对象,采用Matlab、COMSOL等数值模拟软件,建立了上部结构-基础-地基共同作用数值模型,采用连续损伤演化理论,分别分析了地基倾斜、水平拉伸、水平压缩、负曲率、正曲率等采动变形作用下的大型建筑物上部结构、基础等各部位的采动响应。结果表明:地基倾斜变形、曲率变形对建筑物上部结构和基础的变形影响均成整体性,位移量表现为建筑中间部位小、两侧大;地基水平变形对基础的变形影响比较大,对上部结构的变形影响相对较小。地基采动变形对建筑物产生的附加应力多集中在杆系结构的节点处,尤其是在地基水平变形、曲率变形作用下,附加应力主要集中在基础的杆系结构部分。地基曲率变形、水平变形对建筑物的损伤比较大,倾斜变形对建筑物的损伤比较小;建筑物的上部结构损伤明显小于基础部分,整体刚度大的区域损伤明显比刚度小的区域小。研究成果将为沉陷区上方兴建大型建筑物的安全设计与保护提供理论指导。

Large-scale underground mining will cause the overburden to move,deform and even destroy,and form a large-scale subsidence area on the surface.The subsidence area is a bad ground,and there is the possibility of subsidence and deformation.Therefore,large buildings on the subsidence area has a large potential safety hazard.Understanding the interaction mechanism between buildings and ground is the prerequisite for ensuring the safety of the buildings.Taking the large buildings structure as the research object,using the numerical simulation software such as Matlab and COMSOL,the numerical model of the superstructure-foundation-ground interaction was established.The continuous damage evolution theory was used to analyze the mining response of various structures such as the superstructure and foundation of large buildings under the action of the ground inclination,horizontal tension,horizontal compression,negative curvature and positive curvature.the effects of ground inclination and curvature deformation on the deformation of the superstructure and foundation of the building are all integrated,and the displacement of the building is small in the middle and large on both sides;the horizontal deformation of the ground has a greater impact on the deformation of the building foundation,and the deformation of the superstructure is relatively affected smaller.The additional stress on the building caused by ground mining deformation is mostly concentrated at the nodes of the rod structure,especially under the horizontal deformation and curvature deformation of the ground,the additional stress is mainly concentrated on the part of the rod structure of the foundation.The curvature deformation and horizontal deformation of the ground have greater damage to the building,and the inclination deformation has less damage to the building;The deformation of the superstructure is significantly smaller than that of the foundation part,and the deformation of the region with a large overall stiffness is significantly smaller than the region with a small stiffness.The research results will provide theoretical guidance for the safety design and protection of large buildings built above the subsidence area.