块系覆岩破坏对巷道顶板的防冲吸能效应研究

Study of tunnel roof anti-impact and energy absorption effect on block overburden rock mass failure

通过块系覆岩动力传播顶板响应计算,从理论上分析了覆岩破坏程度和破坏深度对岩体动力传播携带能量的耗散作用.结果表明:随着覆岩破坏程度的增大巷道顶板在动载作用下的冲击启动时刻明显延迟,有效延缓了冲击能量的传递,顶板的冲击力、动能和位移响应幅值均随覆岩破坏程度的增大而下降,且顶板冲击力衰减明显,可有效耗散岩体中的冲击能量实现覆岩破坏吸能防冲效果.同时,覆岩破坏深度与顶板位移,冲击力及动能幅值的衰减均呈现正相关性,但其衰减幅度与覆岩破坏深度之间存在非单调变化关系.

By computating tunnel roof response on the dynamic propagation in block overburden rock mass,the influence of overburden rock mass failure degrees and failure depths to impact energy dissipation was studied in theory during the dynamics propagation.The results show that,when failure degrees of overburden rock mass increass,the initial times of tunnel roof response is delaed obviously.It is effectively delay the transmission of shock energy.At the same time,the impact force,kinetic energy and displacement amplitude of tunnel roof are all attenuated.The attenuation of tunnel roof impact force is obviously.Therefore,the impact energy can be dissipated through the failure of overburden rock mass and energy absorption,and antiimpact can be realized by different degrees of overburden rock mass failure.The influence of failure depths in overburden rock mass to energy dissipation is also studied.There is a positive correlation between the attenuation of tunnel roof impact force,kinetic energy,displacement and failure depths in overburden rock mass.But the attenuating range has a non-uniformly variation relationship depend on the overburden rock mass failure depths.