建筑荷载作用下废弃采空区覆岩稳定性及活化机理研究

With the acceleration of urbanization process, the contradiction between the increase of mining-induced subsidence area and the decrease of construction land for urban development is increasingly prominent in the east-central plain mining area. Numerous buildings are inevitably constructed above the abandoned goaf of the coal mine. Under the building load effects, the overlying strata above the abandoned goaf, which was originally in a relatively stable state may be reactivated, and thus bring a potential safety hazard to the stability and safe building facilities. A new idea is proposed to study the stability of overburden above abandoned goaf under building load effects by establishing a mechanical model of load-bearing structure in the overlying strata. The mechanical model of load-bearing structure is established with the consideration of the law of overburden load transfer, and then the deformation response characteristics and stability of the overlying strata above the abandoned goaf is investigated. On this basis, the activation mechanism of overburden above abandoned goaf is revealed and the mechanical criterion of the overburden activation is determined. In the meantime, the effects of the surface movement and deformation on the deformation of building foundation of are investigated based on the time effect of surface movement and deformation due to activation of the overlying strata above abandoned goaf. Finally, the influence mechanism of surface movement and deformation on the stability of building foundation will be revealed with the consideration of the influence of building load on the combined deformation characteristics of overburden, ground surface and building foundation. The results will provide a theoretical basis for evaluating the stability of overburden above the abandoned goaf under building load effects, ensuring the safety of building and serving the engineering construction on the mining-induced subsidence area in the east-central China.

随着城市化进程的加快，中东部平原矿区采煤沉陷区面积增加与城市发展建设用地减少的矛盾日益突出，众多建筑物兴建在废弃采空区之上。建筑荷载作用下，原本处于相对稳定状态的废弃采空区覆岩有可能重新活化运动，对建筑物安全造成重大隐患。课题提出通过建立采动覆岩承载结构力学模型来研究建筑荷载作用下废弃采空区覆岩稳定性的新思路。基于采空覆岩对建筑荷载附加应力传递的影响规律，建立采动覆岩承载结构力学模型，分析建筑荷载对采空覆岩变形响应特征及稳定性特征的影响，揭示废弃采空区覆岩活化机理，确定活化力学判据；研究建筑荷载传递作用下地表移动变形的时间效应，建立地表移动变形对建筑地基变形的影响模型，分析建筑荷载对废弃采空区覆岩、地表、建筑地基的组合变形特征的影响，揭示地表移动变形对建筑地基稳定性的影响机制。课题研究将为评价建筑荷载作用下废弃采空区覆岩稳定性、确保建筑物安全，服务中东部城市采煤沉陷区工程建设提供理论基础。

采煤沉陷区面积增加与城市发展建设用地逐渐减少的矛盾日益突出，针对采煤沉陷区新建建筑物时废弃采空区覆岩活化运动导致地表移动变形并威胁建筑物安全的问题，本项目采用现场调研、实验室试验、理论分析、实验室模拟等方法，进行了建筑荷载作用下废弃采空区覆岩稳定性及活化机理研究。研究分析了建筑荷载作用下采空覆岩承载应力分布特征，建立了采空覆岩承载应力分布函数，揭示了建筑荷载在采空覆岩结构中的传递规律；确定了采空覆岩结构承载范围及其变形特征，明确了建筑荷载对采空覆岩稳定性的影响规律，揭示了建筑荷载作用下采空覆岩活化运动机理，确定了采空覆岩活化运动的力学判据；研究了建筑荷载大小、范围、位置和时间对采空覆岩活化运动及地表移动变形的影响规律，分析了建筑荷载作用下地表移动变形的时间效应，明确了建筑荷载对覆岩、地表、建筑地基组合变形的影响规律，揭示了建筑荷载作用下地表移动变形对建筑地基稳定性的影响机制。.在本项目执行过程中，以首位或通讯作者在Bulletin of Engineering Geology and the Environment、煤炭学报等国内外行业期刊上发表SCI、EI论文7篇，中文核心1篇；申请发明专利4项，其中授权2项；获得山东省科学技术进步一等奖、中国煤炭工业科学技术二等奖、中国岩石力学与工程学会科学技术进步二等奖等科技奖励7项；获山东省高校青创科技团队带头人、全国高校矿业石油与安全工程领域优秀青年科技人才、《中国矿业大学学报》期刊优秀青年编委等。.本课题研究为揭示建筑荷载传递作用下采空覆岩活化机理、进行废弃采空区覆岩稳定性评价提供理论基础，在采煤沉陷区地表工程建设方面具有广阔的应用前景。