摘要
岩爆是长大隧道施工中发生频率较高的突发性地质灾害;岩爆研究对于隧道的勘测设计、施工组织及安全生产具有重要的现实意义。岩爆机理研究是岩爆预测及控制技术发展的基础;由于现有理论的不完善,以之为基础的预报体系及控制技术还不能对岩爆灾害进行准确预报和有效控制。岩石静力学理论在岩爆研究中是重要的,但它还不能阐明岩爆的全部机理。钻爆法开挖过程中,各炮层的顺序起爆、周边眼起爆后开挖轮廓面的瞬时大幅卸载及岩爆事件本身所产生的各类高幅值、陡波前应力波以及它们的叠加效应对于围岩,尤其是处于双向受压、一侧临空、具有发生破坏潜势的既有炮次围岩的扰动作用应该是显著的。围岩也许不会在上述动荷载的一次作用下就发生宏观破坏,但这些应力波的多次扰动,却会在微观-细观尺度上引起围岩累积性损伤的加剧与局部应力环境的恶化,并最终导致裂纹的大规模瞬时动力扩展,伴随晶间、粒间瞬态应变能的高速释放,围岩便会以岩爆的形式失稳。因此,系统进行岩爆灾害的岩石动力学机理研究是必要的。
Rock burst is one of geological hazards encountered frequently in the excavation of long tunnels with large section and the researches on rock burst is of importance to design and safe construction of long tunnels. The rock burst mechanism researches is the basis of the development of prediction and controlling technology. Because of the defects of existing theories about rock burst mechanism, forecasting system and controlling technology based on these theories have not could effectively direct tunnel construction yet. Static rock mechanics is important in rock burst researches, but it can not explain the whole mechanism of rock burst. In drill & blast tunneling, various stress waves stemming from successively detonating of different hole layers, instantly unloading of excavating wall after denotation of perimeter holes and rock burst event itself will disturb notably wall rock, especially excavated surrounding rock. After being disturbed by the dynamic load several times, the wall rock may fail dynamically. So it is necessary to study systematically the dynamic mechanism of rock burst.
出处
《自然灾害学报》
CSCD
北大核心
2004年第2期16-24,共9页
Journal of Natural Disasters
基金
国家自然科学基金资助项目(40272119)
国家自然科学基金重大研究计划项目(90102002)
云南省自然科学基金资助项目(2001E0001G)
关键词
岩爆
隧道施工
地质灾害
机理
岩石动力学
long tunnels with large section
rock burst hazard
mechanism
rock dynamics
