In order to obtain the water inrush mechanism of roof under ultra thick and low permeability aquifer,the variety of methods were carried,including observation of drilling fluid leakage volume,geophysical prospecting,observation of television and numerical simulation. The results showed that the presence of low permeability thick-sandstone aquifer underlying impermeable shale layer in the overburden rock and the ratio 12.51 of the height of the fractured zone to the mining height which spreaded to the sandstone aquifer provide water source,channels and other internal conditions. Through the study of mine transient electromagnetic method and numerical simulation,the storage water space which under mining conditions the combination structure of sandstone and shale( hard rock and soft rock)lead to dis-turbance shale remodeling to form was determined,when the water closed in the storage water space reached a certain degree,with the periedic weighting of main roof and a large area of collapse,the separation water bag burst and instantaneously spurtted into mine,leading to water irruption.On this basis,summing up the methods and experience of abscission layer water effective drainage in process of mining, which provided a valuable reference for similar to water damage prevention.%为得到巨厚低渗含水层下顶板水害形成机理，采用钻孔冲洗液漏失量观测、钻孔电视观测和物探等勘查及数值模拟方法对其进行研究。结果表明：覆岩存在巨厚低渗砂岩含水层，下伏泥岩隔水层，覆岩裂采比为12.51，波及到该砂岩含水层，这为突水提供了水源和通道等内在条件。通过矿井瞬变电磁法探测及数值模拟研究，确定砂岩和泥岩软硬组合结构在采动条件下，扰动泥岩重塑形成离层储水空间，当离层积水量达到一定程度后，伴随着基本顶的周期来压及大面积垮落，离层水包破裂并瞬间溃入矿井，造成突水灾害。在此基础上，总结了开采过程中对离层水进行有效疏放的方法与经验，为类似水害防治提供了借鉴。
展开▼
