重复采动条件下老采空区地质稳定性研究

发布时间：2018-05-25 00:15

本文选题：老采空区 + 综合地球物理勘探　；参考：《安徽大学》2015年硕士论文

【摘要】：近年来,煤矿采空区的探测与研究是地球物理勘探研究的热点,也是煤矿安全生产和矿区环境综合治理的保障。针对基础地质资料的缺乏,重复采动条件下老采空区的复杂性和无规律性的特点,国内外目前还没有形成成熟的理论体系,因此开展综合地球物理探测在复杂采空区应用与研究以及对矿区环境综合治理有着重要意义。本文在国内外煤矿采空区探测现状与理论研究的基础上,收集大量基础资料,总结理论方法,研究分析了老采空区形成的原因及特征。以大通采煤采空区地质稳定性评价为目的,对研究区进行了室外实地调研、综合地球物理勘探、浅层钻探、地表土壤养分评价,室内借助实验分析,从多角度对老采空区进行分析与研究,得到了以下几个方面的认识：(1)受小煤窑后期重复扰动的影响,老采空区发生活化,上覆岩体易发生破碎塌落以及地表二次移动变形,使该区域地质稳定性降低以及地表沉陷,而原有岩层的完整性与连续性被破坏导致的地球物理特征的变化又是综合地球物理勘探的理论前提。(2)通过工程实例,发现以瞬变电磁法与并行网络电法电法测线布设相互补充,浅层二维地震对探测结辅以验证的综合物探方法对老采空探测取得了满意的结果。(3)综合地球物理探测结果表明,研究区视电阻率分布在不同测线剖面的垂直和水平方向上都有显著差异。垂直方向上,150m以浅区域高阻区相对集中,而深部区域高阻区分布不连续且阻值低于浅部,呈高低阻交错的形态；水平方向上,高阻区主要分布在研究区中东部。二维地震勘探反射波剖面显示的异常区域与电法、瞬变电磁法探测一致。三种物探方法相互印证,优势互补,提高了探测成果的可靠性。在成果解释过程中采取以瞬变电磁法和并行电阻法反演成果为主,二维地震勘测结果为辅的综合解释模式,为类似采空区探测提供借鉴。(4)对研究区第四系黏土层研究表明,黏土层为微-极微透水性土层,且厚度稳定,可有效阻隔地表水对地下水的补给,为沉陷区湿地生态系统构建提供有力条件。研究区表层土壤养分评价表明,采空区塌陷造成地表沉陷引发的水土流失加剧是造成研究区土壤养分空间差异的主要原因,土壤养分东高西低,与地表沉陷有一定的空间相关性,通过地表土壤养分评价也可间接反映地质稳定性状况。(5)地质稳定性综合评价结果表明,由于小煤窑的重复扰动影响,研究区中部、东部老采空区易发生活化,属于塌陷不稳定区；其余未受小煤窑采动影响的部分,经过长时间的残余沉降以及上覆岩层的压密,老采空区基本稳定,属于塌陷稳定区。
[Abstract]:In recent years, the exploration and research of goaf in coal mine is a hot spot in geophysical exploration, and it is also the guarantee of safe production in coal mine and comprehensive management of mining area environment. In view of the lack of basic geological data, the complexity and irregularity of the old goaf under repeated mining conditions, no mature theoretical system has been formed at home and abroad. Therefore, it is of great significance to carry out comprehensive geophysical exploration in complex goaf and to improve the environment of mining area. Based on the present situation and theoretical research of goaf detection in coal mines at home and abroad, this paper collects a large number of basic data, summarizes the theoretical methods, and studies and analyzes the causes and characteristics of the formation of the old goaf. In order to evaluate the geological stability of Datong coal mining goaf, outdoor field investigation, comprehensive geophysical exploration, shallow drilling, surface soil nutrient evaluation and laboratory analysis were carried out in the study area. Based on the analysis and study of the old goaf from many angles, it is concluded that the following several aspects are known: 1) affected by repeated disturbance in the late stage of small coal mine, the old goaf is activated, the overlying rock is prone to collapse and collapse, and the secondary movement deformation of the surface occurs. The change of geophysical characteristics caused by the destruction of the integrity and continuity of the original strata is the theoretical premise of comprehensive geophysical exploration. It is found that the transient electromagnetic method and the parallel network electric method complement each other, and the synthetic geophysical exploration method, which is supplemented by shallow two-dimensional earthquakes and verifies the exploration junction, has obtained satisfactory results for the old mining air exploration. The apparent resistivity distribution in the study area is significantly different in the vertical and horizontal directions of different line profiles. In the vertical direction, 150 m is relatively concentrated in the high resistance area in the shallow area, but the distribution of the high resistance area in the deep area is discontinuous and the resistance value is lower than that in the shallow area, which shows the pattern of high resistance interleaving, while in the horizontal direction, the high resistance area is mainly distributed in the central and eastern part of the study area. The anomalous area shown by the reflected wave profile of two dimensional seismic exploration is consistent with that of the electric method and the transient electromagnetic method. The three geophysical methods are proved to be mutually beneficial to each other, and the reliability of the exploration results is improved. In the process of interpretation of the results, a comprehensive interpretation model, which is based on the inversion results of transient electromagnetic method and parallel resistance method and supplemented by two-dimensional seismic survey results, is adopted, which provides reference for similar goaf exploration. It shows that the Quaternary clay layer in the study area is studied. The clay layer is micro- micropermeable soil layer and its thickness is stable, which can effectively block the recharge of surface water to groundwater and provide a strong condition for the construction of wetland ecosystem in subsidence area. The evaluation of surface soil nutrient in the study area shows that the soil erosion caused by the subsidence in goaf is the main reason for the spatial difference of soil nutrient in the study area, and the soil nutrient is low in the east and west. The comprehensive evaluation results of geological stability can also indirectly reflect the geological stability. The results show that, because of the repeated disturbance of small coal mines, the central part of the study area is affected by the repeated disturbance of small coal mines. The old goaf in the east is easy to be activated and belongs to the unstable area of collapse, and the other parts which are not affected by the mining movement of small coal mines, after a long period of residual subsidence and the compaction of the overlying strata, the old goaf is basically stable and belongs to the stable area of collapse.
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD325.3;P631

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