松动爆破作用下的瓦斯抽采效率研究

针对象山煤矿掘进面煤层透气性差、瓦斯涌出量大难题，基于21301掘进迎头地质条件和数值模型试验，开展了松动爆破作用下煤层力学响应与瓦斯抽采效率研究。在瓦斯抽采气-固耦合理论基础上，借助有限元软件分析了爆破后煤层渗透率、瓦斯压力变化规律。数值模型结果表明：在爆破动载荷作用下，煤层的塑性破坏极大的提高了自身的渗透性能。环绕爆破钻孔所产生的高渗透性区域，促使瓦斯向抽采钻孔内快速转移，达到降低瓦斯含量的目的。与现场所收集瓦斯累计流量相对比，验证了松动爆破耦合模型的合理性，最终污风内瓦斯浓度在0.4%。

Study on gas extraction efficiency under loose blasting

For further research on the influence of the blasting effect of gas disaster governance, on the basis of the studies of the xiangshan coal mine, with 21301 tunneling faces as the research object, the establishment of a loose blasting under the action of gas drainage gas recovery - solid coupling model, the effect of the surface loose blasting control the gas on the numerical simulation research results show that the blasting explosive detonation, surrounded by blasting in coal seam drilling dynamic load presents increasing trend, and accompanied by an expansion of the damage area of coal seam, further lead to excavating surface integrity damage of coal seam, the permeability of coal seam After loose blasting, the gas pressure reduction zone generated around the blasting borehole promotes the gas transfer to the surrounding environment and the extraction borehole, so as to achieve the purpose of rapidly reducing gas pressure. Finally, the result of this model is compared with the accumulated gas flow collected on site, verifying the rationality of the gas-solid coupling model of loose blasting.