【作者】 胡戈；

【导师】 李文平；

【作者基本信息】 中国矿业大学 ， 地质工程， 2008， 博士

【摘要】 综放开采技术是近几年发展起来的高效采煤技术。但综放开采易引起导水裂隙带高度的增加和分布范围的扩大,断层的活化更容易引起顶板突水事故的发生。本文对综放开采断层带附近顶板破坏规律及断层活化导水机理进行了研究。通过综放开采煤层顶板破坏过程数值模拟,结合现场实测,得到导水裂隙带最大高度H与煤厚M的关系: H = 9 .46M+7.33断层附近的导水裂隙带高度比无断层处增加约40%。通过三轴加卸载全应力——应变过程测试岩石渗透试验,获得了岩石渗透性与应力应变的关系:在不同的应力、应变状态下,岩石的渗透系数不再是常数;且其峰值基本发生在岩石破坏后应变软化阶段。采用室内钻孔水压致裂模拟法对现场水压致裂试验进行模拟,测得部分岩块的阻水系数。结合岩体结构性参数,得到部分沉积岩体的阻水性能。断层带充填物以泥质为主时,浸水以后呈现泥化状态,具有良好的隔水性和再生隔水性。断层带原始状态下的阻水系数可达到0.12MPa/m。对煤层顶板突水实例进行了分析,并通过自主设计的煤层综放开采顶板断层突水模型试验,测得了不同水压下顶板断层充填物(泥、砂)突出量、突水量随时间变化过程,从采动裂隙岩体力学和渗流理论方面,探讨了综放开采煤层顶板断层活化导水机理如下:煤层采动引起顶部岩层的冒落、破裂,产生导水裂隙带;其上岩层弯曲下沉,断层两盘产生位移(即断层的活化),使得断层带阻水性能下降;在高水压下断层采动活化过程中,断层充填物泥质、砂质依次突出,发生由孔隙流----裂隙流----管道流的渗流转换,最终导致断层突水事故。更多还原

【Abstract】 The fully mechanized top-coal caving is an efficient coal mining technique that has been developed in recent years. But the height and distribution of the fractured zone got enlarged than ever before. The water-inrush accident is happened easily while fault activated. This paper mostly researches on the rule of roof failure near fault belt and the mechanism of water transmitting while fault belt activated in fully mechanized top-coal caving.The author gets the relationship between the maximal height of fractured zone and the thickness of coal seam through numerical simulation and field detection: H = 9 .46M+7.33And the height of fractured zone near fault is about 40% higher than normal.The relationship between permeability and stress-strain of rock is determined through permeability test of complete stress-strain process with stress adding and reducing from three axes. The permeability of rocks is never constant under different stress and stress condition; and the peak value of the rock appears in the stage of strain softening after rock damaging.Hydraulic fracturing field test is analogized through the analogue method of indoor drill hydro-fracturing. And the water resistance coefficient of rock stratum is determined. Parts of water resistance coefficient of derivative rock are determined combining research production of predecessor.When lutaceous mass is in the majority of fault filling and the fault filling appears slimy condition. And the lutaceous mass has good water-Resistant ability and regenerative water-Resistant ability. The water resistance coefficient of fault zone could reach 0.12MPa/m under the original condition.The illustration of water-inrush from roof is analyzed. And the author gets the mechanism of water transmitting while fault belt activated in fully mechanized top-coal caving through by model testing which is independently designed. The process of filling of fault extruded and quantity of water-inrush under different stress is observed. And the mechanism is discussed through mechanics of fractured rock caused by mining and theoretics of seepage.Coal mining gets the falling and fractured of roof, and fractured zone formed, the upper terrane bends and sinks down. All of these bring the displacement of two walls of fault (fault activated), and the water resistance coefficient of fault zone descends. In the process of water-inrush under high stress, seepage conversed from seepage phase to cranny flow phase and pipeline flow phase along with the filling of fault extruded. At last the accident of water-inrush caused by fault occurs.更多还原