危岩崩塌具有突发性,属于能量快速释放的动力学过程.针对压剪型危岩,提出了压剪型危岩破坏力学模型,建立主控结构面锁固段切向抗力和剪切位移本构方程；发现危岩动力失稳瞬间系统的临滑聚能将释放并转换为危岩崩落动能,推导建立了危岩主控结构面锁固段断裂扩展所需耗能的计算公式,得到危岩临滑聚能和临滑释放能量随剪切位移增大的演化曲线,据此提出危岩突发性破坏后崩塌体弹冲速度和弹冲加速度计算公式.研究成果为进一步分析危岩崩落机制及致灾效应具有一定参考借鉴作用.%Perilous rock has a sudden falling feature, this is a dynamic process of rapid energy release. Focusing on a compression-shear perilous rock, its mechanical model was bui and the constitutive equations between locked patch tangential resistance force and shear displacement was established. It was shown that the energy accumulation is released and transformed to the elastic and impulsive kinetic energy at the moment when perilous rock loses its dynamic stability. Meanwhile, the calculation formulas of fracture extending dissipation energy on the locked patch of a dominant fissure were derived. The evolution curve for energy accumulation and energy release of a perilous rock with increase in its shear displacement was gained. Then, a method to calculate the elastic and impulsive velocity and acceleration of a collapse mass after a sudden collapse was proposed. Furthermore, the results provided some scientific basis for further study on collapse mechanism of a perilous rock and its disaster effects.
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