采动条件下覆岩地电场响应特征研究

发布时间：2018-02-09 23:43

本文关键词： 直流电法顶板破坏地电特征动态监测　出处：《中国矿业大学》2015年硕士论文　论文类型：学位论文

【摘要】：煤层顶板受采动破坏影响产生裂隙带和冒落带,易引发顶板突水事故,因此,进行顶板破坏冒落带动态监测具有十分重要的意义。实验表明岩石在破坏过程中电阻率会有明显变化,这一现象成为应用直流电法进行顶板破坏冒落带动态监测的物理基础。本文通过分析顶板覆岩破坏的电阻率变化特征,提出了采动过程中顶板破坏的地球物理监测方法,从而有效的预防顶板突水事故。本文通过对顶板覆岩破坏特征和岩石破坏时电阻率变化规律的研究,依据矿井水文地质特点,建立了不同地质构造、工作面推进不同距离的顶板岩层破坏地电模型,对地电模型进行了直流电法三维正演模拟,并对正演数据进行了反演,得到了工作面推进过程中煤层顶板冒落带发育动态变化的视电阻率断面图。数值模拟结果表明:直流电法能有效探测顶板破坏冒落带和裂隙带,不同构造的视电阻率等值线图差异较大,在不同推进阶段,视电阻率分布规律与顶板冒落带和裂隙带发育范围吻合,为采用直流电法监测顶板破坏冒落带和裂隙带奠定了理论基础。根据物理模拟的相似原理,在实验室中采用物理模型模拟实际探测中的地电模型,结果表明:随着工作面的推进,顶板破坏范围不断增大,视电阻率分布与模型中冒落带与裂隙带范围相符,整体上物理模拟的视电阻率变化特征与数值模拟吻合,进一步验证了直流电法可以用于顶板破坏的监测。结合数值模拟和物理模拟实验结果,对鄂尔多斯某矿工作面顶板受懫动影响破坏动态监测的资料进行解释,得出了鄂尔多斯某矿工作面顶板破坏的范围随着工作面的推进不断增大,冒落带和裂隙带的最大破坏深度分别为20m和50m,破坏范围和视电阻率变化特征与数值模拟和物理模拟的结果基本吻合。地面直流电阻率法能够准确的反映顶板覆岩受懫动影响的电阻率变化特征及顶板所含的地质构造,确定冒落带和裂隙带的范围。通过数值模拟、物理模拟和工程实例的研究和应用,证明直流电阻率法用于监测懫动影响下顶板破坏是切实可行的,具有实际应用的潜力。
[Abstract]:The roof of coal seam is affected by mining failure to produce fissure zone and caving zone, which is easy to cause roof water inrush accident, so, Dynamic monitoring of roof caving zone is very important. The experiment shows that the resistivity of rock will change obviously during the process of failure. This phenomenon has become the physical basis for dynamic monitoring of roof failure and caving zone by using direct current method. This paper presents a geophysical monitoring method for roof failure in mining process by analyzing the characteristics of resistivity variation of roof overburden failure. In this paper, the failure characteristics of roof overburden and the law of resistivity variation during rock failure are studied, and different geological structures are established according to the characteristics of mine hydrogeology. In this paper, the geoelectric model of roof failure at different distances is advanced, and the direct current method is used to simulate the geoelectric model, and the forward data are inversed. The apparent resistivity profile of the dynamic change of the roof caving zone in coal seam during the working face advance is obtained. The numerical simulation results show that the direct current method can effectively detect the roof caving zone and fracture zone. The apparent resistivity isoline maps of different structures differ greatly, and the distribution of apparent resistivity in different stages coincides with the development range of roof falling zone and fracture zone. It lays a theoretical foundation for the direct current electric method to monitor the roof failure falling zone and fracture zone. According to the similarity principle of physical simulation, the physical model is used to simulate the geoelectric model in the laboratory. The results show that with the advance of the working face, the roof failure range increases, and the apparent resistivity distribution accords with the falling zone and fracture zone in the model, and the variation characteristics of apparent resistivity in the whole physical simulation coincide with the numerical simulation. It is further verified that DC method can be used to monitor roof failure. Combined with the results of numerical and physical simulation experiments, the dynamic monitoring data of roof failure affected by movement in a certain coal face in Ordos coal mine are explained. It is concluded that the roof failure range of a certain coal face in Ordos coal mine increases with the advance of the working face. The maximum failure depth of caving zone and fracture zone are 20m and 50m, respectively. The variation characteristics of failure range and apparent resistivity are in good agreement with the results of numerical simulation and physical simulation. The surface DC resistivity method can accurately reflect the roof overburden. The characteristics of resistivity change and the geological structure contained in the roof, which are affected by the movement, Through numerical simulation, physical simulation and application of engineering examples, it is proved that the DC resistivity method is feasible for monitoring roof failure under the influence of movement, and has the potential of practical application.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD327.2;P631.3

【参考文献】