冲击地压威胁下巷道围岩的动力学模型研究

Dynamic Model of Roadway Surrounding Rock Subjected to Rock Burst

将巷道围岩简化为由Bingham体表示的完整岩块与由Kelvin体表示的软弱岩层,建立了冲击地压威胁下的巷道围岩与支护响应的动力学模型,认为可通过减小外界扰动能量、提高支护初撑力(工作阻力)与支护刚度、提高支护阻尼与顶板岩层阻尼等措施来避免或减弱冲击地压灾害,并对其在相应工程生产中的具体做法进行了阐述。认为完整岩块与软弱岩层之间可能可相互转化,当支护力达到一定程度时,相邻软弱岩层可能会闭合成为新的完整岩块,使其自身的强度得到一定的增强,但同时由于其阻尼系数降低其耗散能量的能力也会显著削弱,同理当冲击荷载超过完整岩块强度时,完整岩块也可转化为软弱岩层,在增加了围岩阻尼系数(降低了围岩的刚度)的同时,也降低了围岩的强度,即"强化"作用与"劣化"作用同时存在,而判断采用松动爆破等手段进行转化的好坏,就取决于究竟是增大阻尼系数明显还是降低强度明显。

Roadway surrounding rock is simplified to intact rock represented by Bingham body and weak strata represented by Bingham body, and a dynamic response model of roadway surrounding rock and support subjected to rock burst is established, besides its specific application was analyzed. Several techniques such as decreasing impact energy, improving support setting load （working resistance） and support stiffness, and improving support damp and strata damp are proposed to prevent roadway from rock burst damage. Mutual transformation into each other between intact rock and weak strata may exist, and when the supporting force is larger, the adjacent weak strata may be transformed to new intact rock so that its strength can become larger while its energy dissipation ability be reduced due to its damping coefficient is becoming smaUer. When impact load exceeds the strength of intact rock, intact rock can also be transformed to weak strata, and its damping coefficient is becoming larger （reducing the stiffness of rock） while the strength of surrounding rock is reduced, so ＂enhanced＂ role and ＂deterioration＂ role also exist. The judgment of effects of transformation methods such as loose blasting, depend on which one is larger between increasing damping coefficient and decreasing strength.