井下钻孔电阻率法典型地电模型三维正演模拟

3D forward modeling of typical geo-electric model with borehole resistivity method

为了有效探测工作面底板水害发育情况,保证安全回采,采用井下钻孔电阻率法三维有限元对典型导含水地质异常体模型进行正演模拟;研究了全空间三维有限元正演理论,分析了不同装置类型的电位分布规律,建立了断层、陷落柱、采空区地电模型并进行三维有限元正演模拟,研究了不同地质异常体模型的电位分布情况。模拟结果表明:电位分布呈现低阻区域稀疏而高阻区域稠密的特点,电位梯度呈现低阻区域变小而高阻区域变大的规律;采用井下钻孔电阻率法探测底板水害更贴近目标体,模拟效果好。

In order to effectively detect the development of water damage in the working face floor and ensure the safety of mining, three-dimensional finite element method of borehole resistivity method is used to carry out forward simulation for the model of typical water-bearing abnormal body. In this paper, three-dimensional finite element forward modeling theory of the whole space is studied, the potential distribution rules of different types of devices are analyzed, the geo-electric models of fault,collapse column and goaf are established, and the three-dimensional finite element forward modeling is carried out, and the potential distribution of different geologic abnormal body models is studied. The simulation results show that the potential distribution is characterized by sparse in low resistance region and dense in high resistance region, and the potential gradient is characterized by the law that the low resistance region becomes smaller and the high resistance region becomes larger. It is more close to the target body to detect the floor water damage by borehole resistivity method. The simulation effect of 3 D forward modeling is good.