基于能量平衡模型的煤与瓦斯突出影响因素的灵敏度分析

针对煤与瓦斯突出机制尚不明确、影响因素复杂的问题,在对煤与瓦斯突出的阶段特征和能量耗散规律分析的基础上,考虑到煤岩体应力场分布和突出孔洞特征,建立煤与瓦斯突出三维结构模型,并基于该模型引入围岩弹性潜能,并根据突出后煤体的堆积状态和断裂表面能,计算得出移动功和破碎功,从而构建突出能量条件模型和突出强度预测模型,并结合突出案例进行验证。同时在突出能量条件模型基础上,采用Morris筛选法对突出影响因素的灵敏度进行分析。研究结果表明:瓦斯内能是瓦斯突出的最主要能量来源,在突出过程中起主导作用,突出能量条件模型和强度预测模型的分析结果与实际突出案例偏差较小,可作为突出灾害的预测和分析依据;中梁山矿和化处矿的突出案例中,对于突出强度、瓦斯涌出量和突出能量,吨煤瓦斯含量为主导因素,灵敏度最大,其次是瓦斯扩散系数、瓦斯压力和孔隙率,而岩石的相关参数的灵敏度接近0。

SENSITIVITY ANALYSIS OF FACTORS AFFECTING COAL AND GAS OUTBURST BASED ON A ENERGY EQUILIBRIUM MODEL

Considering the distribution of stress field in coal rock and the features of outburst hole，a three-dimensional structural model describing the coal and gas outburst was established based on the analysis of the stages and the energy dissipation of coal and gas outburst. The elastic potential of rock was introduced into the model and the mobile power and crushing energy were calculated according to the stacking states of coal and surface energy of fracturing. A model of energy conditions and a model of intensity assessment for outburst were established and verified with real cases. Based on the energy condition of outburst，Morris screening method was used to analyze the sensitivity of the influencing factors of outburst. Gas energy is found to be the main energy source of coal and gas outburst and plays the leading role in the process of outburst. The results from the models of outburst energy condition and outburst intensity assessment deviate little from the ones of the actual outburst cases. In the cases of the coal mines at Zhongliangshan and Huachu，the coal gas content is the primary factor affecting the intensity of outburst，the gas emission and the outburst energy and had the highest sensitivity. The gas diffusion coefficient，gas pressure and porosity are found to be secondary and the sensitivity of other parameters of the rock is close to zero.