深部高瓦斯工作面煤体采动扩容特性研究

应用数值模拟、实验室实验、现场实测和理论分析的综合研究方法，对深部高瓦斯工作面煤体采动扩容特性进行了系统研究。研究发现含瓦斯煤体应力峰值前出现扩容现象，煤体初始瓦斯压力对扩容有显著影响，初始瓦斯压力越大，煤体发生扩容的应力临界值越小，瓦斯压力越易发生突变。高瓦斯工作面煤体扩容阶段，瓦斯压力具有采动应力响应特征，采动应力作用下煤体扩容力学行为打破了瓦斯解吸和吸附的平衡，瓦斯压力呈现先降低后升高的瞬变演化。基于深部开采高瓦斯工作面煤体扩容力学特征，考虑煤体瓦斯解吸吸附特性，依据理想气体定律，构建了含瓦斯煤扩容阶段瓦斯压力采动应力响应的数值力学模型，揭示了煤体扩容区瓦斯压力不稳定易突变失稳的内在机理。深部开采煤层在采动应力作用下的扩容是煤与瓦斯动力灾害发生的必要条件，也是灾害防控的主要可控因素，通过降低煤层采动应力集中以控制煤体扩容，可有效消除煤与瓦斯动力灾变隐患。

Coal mining dilatancy characteristics of high gas working face in the deep mine

The coal mining dilatancy characteristics of high gas working face in the deep mine was researched by using the integrated research methods of numerical simulation，field measurement and theoretical analysis.The results show that the coal seam with gas has dilatancy pre-peak stress，and the initial gas pressure has a significant impact on dilatancy，if the coal seam has higher initial gas pressure then the critical value of stress is smaller and gas pressure is more prone to mutation.Stress responses to gas pressure in the dilatancy processes.While the balance of gas desorption and adsorption is overcharged under the action of mining stress，then gas pressure decreases firstly and increases subsequently.Based on coal mining dilatancy characteristics of high gas working face in deep mine，gas desorption and absorption，and ideal gas law，the dynamic mechanics model of mining stress and gas pressure was built for coal seams with gas in the dilatancy processes.Internal mechanism of gas pressure catastrophe destroy in the dilatancy processes was revealed.Coal seam dilatancy is a necessary condition for coal and gas dynamic disaster in deep mines，and is also disaster prevention and the main controllable factor.By decreasing mining stress to control coal seams dilatancy，can effectively eliminate the coal and gas dynamic disaster.