突出煤型煤全应力–应变全程瓦斯渗流试验研究

EXPERIMENTAL STUDY OF GAS PERMEABILITY OF OUTBURST COAL BRIQUETTES IN COMPLETE STRESS-STRAIN PROCESS

以典型煤与瓦斯突出矿井重庆天府矿业有限责任公司的三汇一矿K1煤层的突出煤型煤试件为研究对象,利用自行研制的含瓦斯煤热流固耦合三轴伺服渗流试验系统,进行突出煤型煤在连续加载作用下,全应力–应变过程的瓦斯渗流规律的试验研究。研究结果表明:突出煤型煤在整个全应力–应变过程中,瓦斯流量与煤样的损伤变形的进程密切相关;瓦斯流量先随着轴向应变的增大而逐渐减小,在煤样达到屈服点后,瓦斯流量发展方向发生转变,开始慢慢增大,并在峰后瓦斯流量增速加大;另一方面,瓦斯流量先随着煤样的体积压缩而变小,在煤样开始扩容后,瓦斯流量转为增大,在破裂后阶段瓦斯流量增幅变大;瓦斯流量与轴向应变的关系可用二次函数表示;瓦斯流量随围压的增大而减小。

Based on the briquette specimens of the outburst coal seam K1 of typical coal and gas outburst mine of Sanhui a mine of Tianfu Coal Industry Co.,Ltd. in Chongqing,the experimental study of gas seepage law of outburst coal briquettes in complete stress-strain process under continuous loading is conducted by fluid-solid-heat coupling with triaxial servo-controlled seepage system of coal containing gas. The study results show that gas flow is tightly related with the damage deformation of the outburst coal briquettes during the complete stress-strain process. Gas flow firstly decreases gradually with the increase in axial strain,but it starts to rise after the yielding point of the complete stress-strain process of outburst coal briquettes;and the increasing rate of gas flow also enlarges after the peak point. On the other hand,the gas flow decreases primarily when the coal sample is volume compressed and then reverses to increase after the sample starts on dilatancy. The increasing range of gas flow enlarges after failure phase. The relationship between gas flow and axial strain can be expressed as a quadratic function and the gas flow decreases with the increasing confining pressure.