人工调控围岩防冲减振数值研究

煤矿冲击地压产生的冲击应力波由围岩介质向巷道表面传播,强烈应力波作用致使支护结构严重破坏甚至失效。采用水力割缝、爆破、锚固以及注浆等人工调控技术,改变巷道附近围岩体物理力学性质,形成不同强度的层状结构,使其成为优良耗能体,增强衰减和散射冲击应力波能力,进而减少对支护结构的破坏。利用ANSYS/LS-DYNA非线性显式动力学有限元程序,模拟5种不同人工调控结构类型对耗散冲击应力波的影响。研究结果表明:当巷道附近围岩结构整体强度均匀时,其耗能性能较弱,冲击应力波作用使得巷道剧烈振动,支护结构受到强烈冲击力作用容易发生破坏;采用人工调控技术手段,围岩体形成不同强度的层状结构,具有较强的耗散冲击能作用,大幅度降低冲击应力波振动频率和幅值,支护结构受到冲击作用力明显降低,整体稳定性得到提高。人工调控围岩技术可有效降低冲击地压的振动作用和冲击应力波的强度。

Numerical research on surrounding rock rockburst prevention and damping by artificial regulation

The shockwave generated by rock burst in coal mine spreads from the surrounding rock to the surface of roadway.Supporting structure suffered severe damage and even failure under the action of the strong stress waves.Adopting hydraulic slotting，blasting，anchoring，grouting and other artificial regulation measures，changing the physical and mechanical properties of roadway surrounding rock near the layered structure，forming the layered structure with different strength can enhance the ability that the surrounding rock attenuates and scatter to the shockwave，thereby reducing the bracing structure damage.In this paper，by applying the ANSYS/LS-DYNA nonlinear explicit dynamic finite element program，simulated 5 different structure types of artificial regulation of stress wave to reveal the effects on dissipative shock.The results show that：when the overall strength of roadway surrounding rock is uniformity，the energy dissipation is weak，impact stress wave makes the roadway vibrate violently，supporting structure will be destroyed for the strong impact force；by applying artificial regulation technology，layered rock is formed with different stratified structure，getting the strong energy dissipation capacity，greatly reducing the impact stress wave vibration frequency and amplitude，supporting structures subjected to impact force decrease obviously，improves the global stability.The artificial regulation of surrounding rock technology effectively reduce the impact pressure vibration and impact stress wave intensity.