Shaanxi Zhuyuan Jiayuan Mining Co. , Ltd.

针对我国西北浅埋煤层保水开采关键隔水层N2红土稳定性不足及水资源保护等问题,研究了陕北榆神矿区薄基岩厚土层典型工作面综放开采导水裂隙发育特征及其对N2红土隔水层稳定性的影响程度。结果表明:理论计算得到导水裂隙带发育高度为57.9~113.9m,现场实测所得结果121.10~139.79m;数值模拟分析不同工作面推进距离下导水裂隙带发育规律,当工作面走向长度达到170m后,导水裂隙高度增长缓慢,最大值为96.5m,煤层开采导水裂隙带贯穿基岩后基本发育至N2红土层底部;基于层次分析方法(AHP)构建N2红土层采动损害评价模型,明确了影响N2红土关键隔水层稳定性的主要因素,基于导水裂隙带发育高度、红土层厚度、红土层与主采煤层间距因素评价结果,并考虑红土层残余厚度进行保水开采结果评价,确定隔水层稳定判据,提出基于裂隙发育特征的隔水层稳定性评价方法。研究结果对于陕北煤田类似条件煤炭绿色开采及保水采煤具有重要参考意义。

Aiming at the stability of N2 laterite and the protection of water resources in the key aquiclude of water-preserved mining in shallow coal seams in Northwest China, the development characteristics of water - conducting fractures and their influence on the stability of N2 laterite aquiclude in typical working face of thin bedrock and thick soil layer in Yushen mining area of northern Shaanxi are explored by means of theoretical analysis, numerical simulation and field measurement. The results show that the height of the water flowing fractured zone is 57. 9~113. 9 m by theoretical calculation, and 121. 10~139. 79 m by field measurement. The numerical simulation analysis shows that the development law of water-conducting fracture zone of overburden rock under different working face lengths is similar. When the working face length reaches 170 m, the height of water-conducting fracture increases slowly, and the maximum value is 96. 5 m. The water-conducting fracture zone of coal seam mining basically develops to the bottom of N2 red soil layer after penetrating bedrock. Based on the analytic hierarchy process (AHP), the evaluation model of mining damage of N2 red soil layer is constructed, and the main factors affecting the stability of key aquiclude of N2 red soil are clarified. Based on the evaluation results of the development height of water -conducting fracture zone, the thickness of red soil layer and the distance between red soil layer and main coal seam, and considering the residual thickness of red soil layer, the results of water - preserved mining are evaluated, and the stability criterion of aquiclude is determined.

1 基本工程地质特征
1.1 工程概况
1.2 N2红土地质组成
2 薄基岩厚土层综放开采覆岩损害特征
3 采动导水裂隙发育规律及对N2红土层的影响
3.1 工作面采动导水裂隙发育规律
3.1.1 数值分析
3.1.2 现场实测
3.2 N2红土隔水层采动破坏影响程度
4 N2红土隔水层采动破坏主控因素分析与评价
4.1 N2红土隔水层采动破坏影响因素分析
1)红土层厚度。
2)红土层与煤层间距。
3)导水裂隙带发育高度。
4.2 基于层次分析法的N2红土层采动损害评价
1)层次分析模型构建。
2)确定评估指标权重。
3)基于层次赋权的N2红土采动损害评价。
4.3 保水开采结果分析
5 结 论

张金金, 杜 航, 张嘉晨, 等. 浅埋煤层综放开采导水裂隙发育特征及隔水层稳定性研究 [J]. 煤炭工程,2024, 56(1): 78-85.