赵庄矿峰峰组碳酸岩层隔水性能研究及应用

Research on Water-resisting Property of Carbonate Strata in Fengfeng Formation in Zhaozhuang Coal Mine and Its Application

为解决山西晋煤赵庄矿下组煤水压高、传统隔水层薄所带来的安全带压开采问题,采用水文地质钻探、抽水试验、压水试验、地应力测试及室内试验等技术手段,通过对奥灰顶部岩性、裂隙岩溶充填情况、钻探漏水、岩石力学指标及渗透性试验等各方面的综合研究,论证了下组15#煤底板奥灰顶部峰峰组岩层的相对隔水性。结果表明:赵庄矿15#煤下伏的奥陶系顶部峰峰组上段岩性为深灰色厚层石灰岩,致密坚硬,局部夹白云质灰岩和泥灰岩,强度较高,裂隙多呈不规则状且大量被充填,构成渗透性很差的岩层;本区奥灰峰峰组顶部至少存在30m厚度的相对隔水层段,15#煤底板隔水层厚度在38. 75~67. 25m之间,平均厚度为57m,且隔水性能较好;采用突水系数法对赵庄矿开采下组15#煤突水危险性评价,说明利用奥陶系顶部相对隔水层可使突水危险性大幅降低,从而解放大量煤炭资源。

To solve the problem of mining under safe water pressure of aquifer with high water pressure and thin traditional water-resisting layer in lower coal seams of Zhaozhuang Coal Mine in Shanxi Jincheng Mining Group, by adopting hydrogeological drilling, pumping test, water injection test, in-situ stress measurement and indoor test, based on the comprehensive study on the lithology, filling situation of fractured karst, drilling leakage, rock mechanical index and permeability test in the top of Ordovician limestone,the relative water-resisting property of rock strata in Fengfeng Formation in the top of Ordovician limestone which is the floor of lower 15#coal seam is demonstrated. The results show that: the lithology of the upper Fengfeng Formation existed in the top of underlying Ordovician as floor of 15#coal seam in Zhaozhuang coal mine is dark grey,dense,hard and thick-layer limestone with less dolomitic limestone and marl,which has high strength and a large number of irregular filled fractures and constitutes strata of poor permeability. There is a layer of relative aquifuge with at least30 m thick existing in the top of Fengfeng Formation of Ordovician limestone. The thickness of underlying water-resisting layer as floor of 15#coal seam is between 38. 75 ~ 67. 25 m and the average thickness is 57 m,which has better water-resisting property. The risk assessment of water-inrush during mining lower 15#coal seam in Zhaozhuang coal mine is performed by the method of water-inrush coefficient,which shows that the risk of water-inrush can be greatly reduced by applying the relative water-resisting layer in the top of Ordovician,and then a great amount of coal resources will be released.