不同采煤方式对边坡的控制作用研究

发布时间：2018-06-20 04:47

本文选题：采动滑坡 + 控坡作用　；参考：《太原理工大学》2017年硕士论文

【摘要】：煤炭资源的开采造成了大范围的采煤沉陷,导致上覆岩土体结构破坏,并逐渐影响到地表坡体的稳定性。在降雨、地震等条件下容易导致山体滑坡的发生,进而威胁到周围人民群众的生命财产安全。由煤炭资源开采所引起的滑坡问题,以往的研究侧重于地表移动而对坡体与采空区塌陷的相关性、协调性涉及相对较少。因此,研究采动滑坡灾害的形成机理以及采煤方式对坡体的控制作用是减少矿山滑坡灾害,合理利用矿产资源,改善矿山环境的关键,其研究具有一定的经济价值和社会意义。本文首先对采动滑坡的主要类型以及常见的失稳破坏模式进行归纳总结,并对研究区采动滑坡的类型进行分析。其次从开采前后坡体的力学特性、地形地质条件、降雨因素以及地下开采与坡体滑动的直接关系等角度分析采动滑坡的形成机理,结果表明:采动滑坡的形成过程主要分为五个阶段:煤层开采阶段—中部下陷阶段—后缘拉裂阶段—前缘剪切阶段—滑坡发生阶段。在上述分析的基础上,根据研究区采动滑坡的实际情况建立对应的数值模型,对煤层开采条件下坡体的位移、应力、应变等方面进行分析。结果表明:采空区形成后顶板上覆岩层整体下沉,并对边界上方岩体产生拉张作用,使其产生倾倒拉裂破坏。之后顶板的沉陷逐渐影响到地表坡体的稳定性,造成坡体后缘产生拉张裂缝,坡体中部则产生弯曲变形并加速了坡体的蠕动,而坡脚处则受到上部坡体的推动作用从而产生剪切变形。最后以研究区采动滑坡为典型实例,模拟采动边坡在不同开采方式下的位移、应力、应变的变化,探讨不同采煤方式对边坡移动变形的控制作用。结果表明:顺向全采相比逆向全采更有利于滑坡的形成,而两端逼近式全采则相比中部扩散式全采更为有效的控制坡体的变形;条带开采虽然能够利用煤柱阻止上方坡体的下沉,从而有效的降低顶板岩层的应力传递,但是这种采煤方式的回采率相对较低,易造成煤炭资源的浪费;充填开采(即采即充法)是能够最大限度提高回采率以及上方坡体稳定性的采煤方式,充填体的灌入使得煤层顶板的扰曲度显著降低,大大缓解了上部岩体的沉降,进而有效的控制坡体的应力分布。
[Abstract]:The mining of coal resources causes coal mining subsidence on a large scale, which results in the destruction of the structure of overlying rock and soil, and gradually affects the stability of the surface slope body. Under the condition of rainfall and earthquake, it is easy to cause landslide, and then threaten the safety of people's life and property. The study of landslide caused by coal resource mining has focused on the surface movement and the correlation between slope body and goaf collapse, and the coordination is relatively little. Therefore, the study on the formation mechanism of mining landslide and the control effect of mining mode on slope body is the key to reduce the landslide disaster, make rational use of mineral resources and improve the mine environment. The study has certain economic value and social significance. In this paper, the main types and common failure modes of mining landslide are summarized, and the types of mining landslide in the study area are analyzed. Secondly, the forming mechanism of mining landslide is analyzed from the aspects of mechanical characteristics of slope body before and after mining, topographic and geological conditions, rainfall factors and the direct relationship between underground mining and slope body sliding. The results show that the forming process of mining landslide is mainly divided into five stages: coal seam mining stage, central subsidence stage, back edge pulling stage, leading edge shear stage, and landslide occurrence stage. On the basis of the above analysis, the corresponding numerical model is established according to the actual situation of mining landslide in the study area, and the displacement, stress and strain of the slope body under the condition of coal seam mining are analyzed. The results show that the overlying strata on the roof of the goaf after the formation of the goaf have a whole subsidence and tension effect on the rock mass above the boundary, resulting in the collapse and fracture of the rock mass. Then the subsidence of the roof gradually affects the stability of the slope body, resulting in the extension crack in the back edge of the slope body, and the bending deformation in the middle of the slope body, which accelerates the creep of the slope body. And the bottom of the slope is driven by the upper slope body, resulting in shear deformation. Finally, taking the mining landslide in the study area as a typical example, the changes of displacement, stress and strain of mining slope under different mining modes are simulated, and the control effect of different mining modes on slope movement and deformation is discussed. The results show that the forward full mining is more favorable to the formation of landslide than the reverse full mining, while the two ends approaching full mining is more effective in controlling the deformation of slope body than that of the central diffusive full mining. Although strip mining can use coal pillar to prevent the subsidence of the upper slope body, thus effectively reduce the stress transfer of roof strata, but the recovery rate of this mining method is relatively low, which can easily lead to the waste of coal resources; Filling mining (that is, mining and filling method) is a coal mining method which can maximize the recovery rate and the stability of the upper slope body. Filling with the filling body can significantly reduce the perturbed curvature of the roof of the coal seam and greatly alleviate the settlement of the upper rock mass. The stress distribution of slope is controlled effectively.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD82

【参考文献】