摘要
为进一步认识煤与瓦斯突出动力现象及其能量释放机制,利用多场耦合煤矿动力灾害大型模拟试验系统开展不同三维地应力条件下的煤与瓦斯突出物理模拟试验,研究突出过程中煤体内瓦斯压力的时空演化过程及其对不同地应力条件的响应规律。结果表明:突出启动后,卸压区的瓦斯压力在下降过程中出现了不同程度的周期性回升现象,卸压区最小主应力方向上瓦斯压力的下降速率随着距煤体断面中心距离的增加而减小,而在最大主应力方向上瓦斯压力的下降呈现出"同增同减"的下降趋势;应力集中区的瓦斯压力下降速率在最小主应力方向上呈现出与卸压区相同的规律,在最大主应力方向上,瓦斯压力下降起始时刻随着地应力的增加而提前,这意味着地应力越大突出扩展至煤层深部的时间越短;瓦斯压力在突出启动初期呈现出半椭圆形压降区,突出过程中煤层内的瓦斯压力下降区向煤层内的扩展是一个减速过程,但随着地应力的增大,瓦斯压降区向煤层深部的推进速率会增大。
In order to further understand the dynamic phenomenon of coal and gas outburst and its energy release mechanism,a large-scale simulation test system for coupled field coal mine dynamic disasters was used to carry out physical simulation tests of coal and gas outburst under different geostress conditions. The spatiotemporal evolution of gas pressure in coal during the coal and gas outburst and its response to different geo-stress conditions were investigated. The results show that,after the start of the outburst,the gas pressure in the distressed zone produces a cyclical rise to varying degrees during the decrease process. In the distressed zone,the drop rate of the gas pressure in the direction of minimum principal stress increases with increasing the distance from the center of the coal section,while the decrease of the gas pressure shows a downward trend of "simultaneous increase and decrease" in the direction of maximum principal stress. In the stress concentration zone,the drop rate of the gas pressure in the direction of minimum principal stress shows the same law as that of the distressed zone,while the initial moment of the decrease of the gas pressure in the direction of maximum principal stress advances with increasing the geo-stress,which means that the greater the geo-stress,the shorter the time for the outburst to propagate deep into the coal seam. The gas pressure shows a semi-ellipsoidal pressure drop zone in the initial stage of the outburst. The process of the gas pressure drop zone advancing in the deep coal seam during the outburst process is a deceleration process. Nevertheless,with,increasing the geo-stress,the expansion rate of the gas pressure drop zone to deep coal seam increases.
作者
彭守建
杨文健
周斌
许江
程亮
杨孝波
PENG Shoujian;YANG Wenjian;ZHOU Bin;XU Jiang;CHENG Liang;YANG Xiaobo(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;School of Resources and Safety Engineering,Chongqing University,Chongqing 400044,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2020年第9期1762-1772,共11页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点研发计划(2018YFC0808303)
国家自然科学基金资助项目(51974041)
重庆市基础与前沿研究计划项目(cstc2018jcyjAX0626)。
关键词
采矿工程
煤与瓦斯突出
三轴应力
瓦斯压力
时空演化
mining engineering
coal and gas outburst
triaxial stress
gas pressure
spatiotemporal evolution
作者简介
彭守建(1983-),男,2011年于重庆大学采矿工程专业获博士学位,现任副教授、博士生导师,主要从事煤与瓦斯突出灾害动力学与控制方面的教学与研究工作。E-mail:sjpeng@cqu.edu.cn。
