不同加卸载条件下含瓦斯煤力学特性及渗透规律研究

With the increasing of the mining depth, crustal stress and gas pressure increase and the coal seam permeability decreases, the gas disaster accidents frequently occur. Because of the influence of mining, stress of coal and rock redistributes and go through the interaction of complex loading and unloading stress paths. Formerly the conventional loading methods were used on the study of coal and rock mechanics and seepage characteristics, but they are quite different from the actual situation. Therefore, based on "domestic-developed triaxial servo-controlled seepage equipment for thermal-hydrological-mechanical coupling of coal containing methane" and "large-scale multifield coupling mining simulation test equipment of coal containing methane"，the experimental study on mechanical properties and seepage law of coal containing methane under different loading-unloading conditions will be performed in this project which combines the experimental research and theoretical analysis and numerical simulation methods. The damage constitutive model and permeability dynamic evolution model of coal containing methane under different loading-unloading conditions will be established. At last, fluid-solid coupling and the gas migration law of coal containing methane under different loading-unloading conditions are simulated and analyzed by a numerical calculation method. In general, the research has an important theoretical and practical significance on mechanism of gas disaster and simultaneous extraction of coal and gas.

随着煤矿开采深度的增加，地应力、瓦斯压力增大，煤层的渗透性降低，瓦斯灾害事故频繁发生。由于采动的影响，煤岩应力发生重新分布，经历了加载和卸载共同作用的复杂应力途径。以往多采用常规的加载方式对煤岩的力学和渗透特性进行研究，这与实际情况有较大的差异。为此，本项目采用实验研究、理论分析、数值模拟等相结合的方法，采用自行研制的"含瓦斯煤热流固耦合三轴伺服渗流实验装置"、"多场耦合煤矿动力灾害大型模拟试验系统"等，对不同加卸载条件下含瓦斯煤的力学特性和渗透规律进行试验研究，揭示不同加卸载条件下含瓦斯煤的力学及渗透特性等变化规律；建立不同加卸载条件下含瓦斯煤的损伤本构模型和渗透率动态演化模型；采用数值计算的方法，对含瓦斯煤在加卸载条件下的流固耦合及瓦斯运移规律进行数值模拟分析。该项目的研究能从新的角度揭示瓦斯灾害的发生机理并对煤与瓦斯的共采具有重要的理论和实际意义。

在深部煤炭资源开采过程中，由于钻孔、钻井和煤层开采等工程扰动行为的存在，煤岩应力会发生重新分布，经历了加载和卸载共同作用的复杂应力途径。以往多采用常规的加载方式对煤岩的力学和渗透特性进行研究，这与实际情况有较大的差异。为此，本项目采用实验研究、理论分析、数值模拟等相结合的方法，采用自行研制的“含瓦斯煤热流固耦合三轴伺服渗流实验装置”、“多场耦合煤矿动力灾害大型模拟试验系统”等，对不同加卸载条件下含瓦斯煤的力学特性和渗透规律进行了试验研究，揭示了不同加卸载条件下含瓦斯煤的力学及渗透特性等变化规律；建立了不同加卸载条件下含瓦斯煤的渗透率动态演化模型。采用数值计算的方法，对含瓦斯煤在加卸载条件下的流固耦合及瓦斯运移规律进行了数值模拟分析。该项目在执行期间出版专著2部，发表学术论文33篇，其中：SCI论文12篇，EI论文20篇，核心期刊论文1篇。项目执行期间新申请国家发明专利23项，获得授权国家发明专利24项（包括前期申请，执行期间获得授权）。项目组在执行期间培养了出站博士后1人、毕业博士生5人、硕士生4人，其中2人获“重庆市优秀博士论文奖励”。该项目的研究成果从新的角度揭示了瓦斯灾害的发生机理并对煤与瓦斯的共采具有重要的理论和实际意义。