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为分析深部巷道围岩层裂薄板结构的形成机制和屈曲型岩爆发生的力学机理,采用数值模拟方法对深部巷道开挖过程中围岩主应力的分异演化规律进行了研究。基于三参量黏弹性本构关系,以屈曲型岩爆的层裂薄板结构为力学模型,推导出了二向受力下屈曲型岩爆的压屈时效方程,探讨了不同应力状态下屈曲型岩爆的时效特征。结果表明:在以垂直应力为主导的巷道在掘进过程中,巷道顶部和底部的主应力水平在逐步减小,岩体能量逐步释放;而巷道两侧边墙的主应力出现严重的分异现象,切向应力变大而轴向应力减小,岩体能量向两侧转移并大量积聚。以水平应力为主的巷道在掘进过程中,围岩应力状态的演化过程及能量积聚特征与此相反。围岩层裂薄板结构形成后,在切向应力和轴向应力的二向应力作用下发生蠕变弯曲变形,经过一段时间,当变形达到某一限值时,层裂薄板结构就会发生屈曲失稳破坏并释放岩体内积聚的弹性变形能,产生延迟岩爆现象。
In order to analyze the formation mechanism of surrounding rock stratified thin walls and the mechanical mechanism of buckling rockburst in deep roadway, the principle of differential evolution of main stress of surrounding rock during deep excavation was studied by numerical simulation method. Based on the three-parameter viscoelastic constitutive relationship, the buckling-type rock burst buckling-age equation under two-direction force is deduced from the mechanical model of buckling-type rock burst. The buckling- Explosive aging characteristics. The results show that during the excavation process, the main stress level at the top and bottom of the tunnel gradually decreases and the energy of the rock mass is gradually released. The main stress of the sidewalls on the sides of the tunnel shows serious differences , The tangential stress becomes larger and the axial stress decreases, and the energy of rock mass is transferred to both sides and accumulates in a large amount. In horizontal tunneling, the evolution process of stress state and the energy accumulation feature of surrounding rock are the opposite. After the formation of the surrounding rock cracked sheet structure, the creep bending deformation occurs under the effect of the two-direction stress of the tangential stress and the axial stress. After a certain period of time, when the deformation reaches a certain limit, the cracked sheet structure will buckle Unstable failure and release of elastic deformation energy accumulated in the rock mass, resulting in delayed rock burst phenomenon.