【作者】 吕义清；

【导师】 刘鸿福；

【作者基本信息】 太原理工大学 ， 采矿工程， 2013， 博士

【摘要】 井工开采可导致斜坡岩(土)体内部应力重新分布,从而可引起岩(土)体变形,并在一定条件下导致斜坡失稳,失稳斜坡不仅威胁到其周边人民的生命财产安全,甚至可造成人员伤亡和经济损失。然而,井工开采引起的斜坡破坏变形的研究,多以将坡体划分为多层水平面受采煤沉陷引发坡体变形移动进行研究的,这一研究对井工开采引起的整体斜坡破坏变形的认识是不足的,尤其是不能有效地给出不稳定坡体变形引发滑坡的范围和有关特征,影响到对其稳定性的评价,使得防治措施针对性差。因此,对井工开采条件下斜坡变形破坏模式、变形破坏机理及其稳定性研究是值得研究的。本文首先就井工开采条件下的斜坡变形模式进行了研究,根据不同的地质与采煤等条件建立了108个典型岩土质斜坡破坏模型,运用现代数学理论以及采煤沉陷理论,分别模拟计算了井工开采条件下不同斜坡的变形特征,模拟计算表明：坡体随着坡度增加,变形趋势增大；随着井工开采埋深增大,变形减小;随着井工开采规模(开采厚度、开采范围)的增大,变形趋势增大；而岩层倾角的变化对失稳坡体变形影响较小。其次本文选择具有山区井工开采条件下代表性的斜坡-太原市古交风峁顶斜坡为典型实例,根据斜坡在井工开采下变形特征,和斜坡所处地质环境条件,并结合斜坡变形监测实测资料,给出了该斜坡变形破坏具有分带性的特征,具体是：坡脚的水平-隆起变形带、坡腰的水平位移-下沉变形强烈带及坡顶的水平位移-下沉变形减弱带；并通过地表移动变形预计模型的计算和综合分析认为,井工开采引起的失稳斜坡变形机理是：地下采空一坡顶沉陷变形一坡体失稳一坡体后缘拉裂一前缘鼓起。在上述工作的基础上,论文根据风峁顶斜坡实际情况建立了地质模型,然后结合开采条件下的斜坡变形模式,建立了数值模型,并对该斜坡在井工开采影响下的应力应变变化进行了模拟；同时又分别对井工开采情况下该斜坡体内是否存在断层的地质条件,建立了的地质和数值模型,并通过模拟给出了该斜坡无断层和存在断层情况下该斜坡破坏变形过程是：井工开采条件下无断层的斜坡破坏变形应力、应变分布范围与程度均较存在断层情况下的斜坡破坏变形小,即地下一定规模的采空区是影响斜坡稳定的主要因素,若斜坡内存在断层,该不稳定斜坡破坏变形将会进一步加大。最后运用极限平衡分析的传统条分法(Morgenstern-Price),采用SIGMA/W及SLOPE/W模块对该不稳定斜坡在天然、暴雨工况下的稳定性状态进行了分析与计算,同时比较了在未进行地下采煤活动时该斜坡在天然、暴雨工况条件下的稳定性状态,给出了不同情况下,该斜坡的稳定系数,从而得到：井工开采前,该坡体处于基本稳定状态；井工开采后,天然工况下该坡体处于变形状态,而在天然+暴雨工况下该坡体处于极不稳定状态。更多还原

【Abstract】 Underground mine exploitation can result in the redistribution of stress in rock (soil) slope, so the rock or soil will deform, and even make failure. The failure of slope not only threatens people and their property, but also leads to casualty and economic losses. For early study on this kind of deformation and failure of the slope, scholars usually divide the slope into some levels which make deformation induced by mine exploitation. This kind of study method can not explain completely the deformation and failure induced by exploitation subsidence. Especially, it can not effectively determine landslide scope and feature induced by the deformation of the instable slope, which will influence the stability evaluation of the slope and the pertinence of prevention measures. Above all, it is very significant for the study on the deformation and failure mode, mechanism, as well as stability due to underground mine exploitation.The deformation mode of the slope induced by underground mine exploitation was studied firstly. According to different geology and exploitation conditions, one hundred and eight failure modes of typical rock and soil slope were established. Using modern mathematics theory and coal mining subsidence theory, the different deformation characteristics of the slope were simulated and calculated under the condition of underground mine exploitation. Simulation results showed that the deformation would become intense with slope gradient increasing; The deformation would become weak with deeper exploitation; The deformation would become intense with larger exploitation mining scale (exploitation thickness, exploitation scope).Taking Fengmaoding slope located in Taiyuan Gujiao as a typical engineering example, which is the typical slope with the condition of underground mine exploitation. Based on the deformation feature under the condition of underground mine exploitation and geological environment, combined with factual monitoring data of slope, it was found that the slope deformation was characterized by zonation. Specifically, slope toe showed horizontal displacement-ridge deformation; Slope waist showed horizontal displacement-intense subsidence deformation; And slope top showed horizontal displacement-weak subsidence deformation. Based on the comprehensive analysis on forecasting model of ground surface movement, the deformation mechanism of the slope under the condition of underground mine exploitation was the sequence below:underground exploitation, subsidence deformation on the top of the slope, slope failure, back edge cracking, and front edge extruding and uplifting.Based on these works above all, according to the factual information of the Fengmaoding slope, geological model was established. Combined with the deformation mode of the slope under the condition of exploitation, numerical model was established. And the stress and strain in the slope under the condition of mine exploitation were simulated. Under the condition of ground mine exploitation, geological and numerical models were established respectively with/without fault in the slope. The slope deformation and failure process from simulation results showed that under the condition of underground mine exploitation, the deformation and failure distribution scope and extent of stress and strain in the slope without fault were less than them with fault. In other words, underground goaf was the main factor influencing the stability of slope, and the deformation and failure would become larger with fault in the instable slope.In the end, based on the method of Morgenstern-Price from limited balance theory, using SIGMA/W and SLOPE/W modules, stability of the slope was analyzed and simulated respectively under the condition of nature or heavy rain, with mine exploitation or not. And the resulting factors of stability were gotten under different condition. It was found that the slope was basically stable before mine exploitation, and it would make deformation after mine exploitation under the natural condition. It would become very unstable under the condition of heavy strain.更多还原