Study on disaster-causing law of different types of hidden structures in deep coal seam
ZHANG Jianguo;QIU Liming;WANG Man;PENG Yujie;LIU Qiang;SONG Dazhao
深部开采过程中,矿井地质类型复杂,在“三高一扰动”条件下,隐伏构造附近极易引发煤与瓦斯突出等煤岩动力灾害。为明确隐伏构造诱发动力灾害的机制,以平煤股份八矿为工程背景,数值模拟研究了不同采掘方向正、逆断层及两者同时存在时的应力−应变演化特征及致灾规律,分析了不同隐伏构造对掘进头的影响。结果表明:掘进遇单一断层,应力−应变集中在工作面前方及断层内部,掘进遇正断层更易产生应力集中,且应力集中区域范围更大,在同等掘进距离下,逆断层主应变略大于正断层;随着掘进距离的增加,当掘进距离增加至15 m时,应力−应变集中区逐渐重合,最终在断层区域形成应力−应变叠加区;掘进遇多断层,应力集中在工作面前方、两断层之间的构造煤上。遇正−逆断层、逆−正断层,叠加应力−应变分布特征表现出差异性,遇正−逆断层,叠加应力−应变主要分布在正断层附近,而遇逆−正断层,两断层之间构造煤中应力−应变也显著增加。逆断层及逆断层主导的多隐伏构造附近,应变能增长速率更大,更有利于应变能积聚,煤与瓦斯突出危险性增加。在采动应力、断层构造应力及煤岩体中的静应力三者的共同作用下,最终引发煤与瓦斯突出等煤岩动力灾害。多隐伏构造较单一构造更易产生应力集中,煤岩动力灾害危险性增加。
In the process of deep mining, the geological type of the mine is complicated. Under the condition of “three heights and one disturbance”, it is easy to cause coal and gas outburst and other coal and rock dynamic disasters near the hidden structure. In order to clarify the mechanism of dynamic disasters induced by hidden structures, taking No.8 Mine in Pingdingshan as the engineering background, the stress-strain evolution characteristics and disaster causing law of normal and reverse faults in different mining directions and their simultaneous existence are studied by numerical simulation, and the influence of different hidden structures on driving face is analyzed. The results show that when driving encounters a single fault, the stress-strain is concentrated in front of the work and inside the fault. Normal faults are more likely to produce stress concentration, and the range of stress concentration is larger. At the same driving distance, the principal strain of the reverse fault is slightly larger than that of the normal fault. With the driving distance increases, when the driving distance increases to 15 m, the stress-strain concentration area gradually coincides, and finally a stress-strain superposition area is formed in the fault area. When driving encounters multiple faults, the stress is concentrated on the structural coal in front of the working face and between the two faults. The superimposed stress-strain distribution is different in the case of normal-reverse faults and reverse-normal faults. In the case of normal-reverse faults, the superimposed stress-strain is mainly distributed near the normal faults. In the case of reverse-normal faults, the stress-strain in structural coal between the two faults also increases significantly. Near the multiple hidden structures dominated by reverse faults and reverse faults, the increase rate of strain energy is larger, which is more conducive to the accumulation of strain energy, and the risk of coal and gas outburst increases. Under the combined action of mining stress, fault structural stress and static stress in the coal rock mass, coal and gas outburst and other coal and rock dynamic disasters are eventually triggered. Multiple hidden structures are more likely to produce stress concentration than single structures, and the risk of coal and rock dynamic disaster increases.
deep coal seam;hidden structure;coal and rock dynamic disasters;stress-strain evolution characteristics;disaster-causing law
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会