复杂断层矿区地下水三维数值模拟

Three-dimensional numerical simulation of groundwater in mining areas with complex faults

为了提高复杂断层矿区地下水数值模拟结果的准确度,以内蒙古某矿区错综分布的10条倾斜断层为研究对象,采用FEFLOW软件将倾斜断层简化处理为垂直透水断层,建立复杂断层矿区地下水三维数值模型,并预测了矿区开采30年后对上覆各含水层的破坏程度。结果表明:二叠系山西组砂岩裂隙含水层受开采直接影响,最大降深约150.23 m;上覆二叠系石盒子组砂岩裂隙含水层和新近系砂砾石含水层无稳定隔水层,水位差的加剧导致越流量增加,最大降深约23 m;第四系松散孔隙含水层由于下部完整且较厚的黏土层,基本上不受影响。对断层的有效概化有助于提高数值模型的仿真性和结果的精准度。

In order to improve the accuracy of results of numerical simulation of groundwater in mining areas with complex faults,we conducted a case study in a mining area in Inner Mongolia, where ten inclined faults were intricately distributed. We used the FEFLOW software to simplify the inclined faults as vertical permeable faults, and established a three-dimensional numerical model of groundwater in the mining area with complex faults. Using the model,we predicted the destruction of the overlying aquifers in the mining area after 30 years. The results show that the drawdown of the Permian Shanxi formation aquifer, affected by exploitation, was about 150. 23 m. The drawdown of the Permian Shihezi formation aquifer and the Neogene aquifer was about 23 m, which was because the water level difference intensified,leading to the increase of flow,and there was no steady aquifuge. The quaternary loose rock pore aquifer was not affected due to the integrated and thick clay layer. The study shows that effective generalization of faults is helpful to improve the accuracy of numerical simulation and its results.