深部矿井冲击地压、瓦斯突出复合灾害发生机理

为了探索深部矿井冲击地压、瓦斯突出复合灾害机理，为复合灾害的有效监测与防治提供理论基础，通过试验研究和理论研究相结合的研究方法，研究了瓦斯对煤岩体力学性质和冲击倾向性的影响，建立了圆形巷道冲击地压、瓦斯突出复合灾害模型并进行了解析分析，探讨了冲击地压和煤与瓦斯突出的诱导转化机理。结果表明:随着瓦斯压力的增大，煤岩体强度降低，弹性模量减小，峰值应变减小，冲击倾向性降低;煤岩体应力存在一个临界值，当煤岩体应力超过临界煤岩体应力时，系统失稳发生冲击地压、瓦斯突出复合灾害;冲击地压、瓦斯突出复合灾害的临界煤岩体应力随瓦斯压力的增加而减小，随煤岩体强度的增大而增大，随冲击倾向性的增大呈现先减小后增大的趋势;冲击地压诱导瓦斯突出多发生在煤岩体中存在含气封闭断层等储气构造或煤层底板含有高弹性模量岩层(夹层)等情况，瓦斯突出诱导冲击地压多发生在软硬煤相间、相互包裹的煤层或突出过程中破碎煤岩体的抛出形成较大的空顶面积等情况。

Mechanisms of rockburst and outburst compound disaster in deep mine

To explore the mechanisms leading to the compound disaster of rockburst and outburst,and to provide a theoretical basis for its effective monitoring and prevention through theoretical analysis and laboratory tests,this study investigates the influence of gas on the mechanical properties and rockburst tendency of coal rock,establishes the rockburst and outburst compound disaster model of circular roadway,and explores the induced transformation mechanisms of rockburst and outburst.The results show that the strength,elastic modulus and peak strain of coal rock all have a negative correlation with gas pressure.At the same time,the rockburst tendency of coal rock decreases with the increase of gas pressure.There exists a critical value of coal rock stress,when the coal rock stress exceeds the critical stress value,the system loses its stability and rockburst and outburst compound disaster occurs.The critical stress increases with the increase of gas pressure and coal strength,and it first decreases and then increases with the increase of rockburst tendency.Outburst induced rockburst occurs mostly in a soft and hard coal seam.Rockburst induced outburst occurs mostly under a situation which the gas storing structures,such as a gas bearing closed fault,exist in the coal body or a high elastic modulus strata exists in floor.Outburst induced rockburst may also occur in another situation during which the ejection of a fragmentized coal body forms a larger empty support area during the process of outburst.