采矿活动是危岩崩塌灾害的主要诱发因素之一，本文以磨子岩W2危岩体为物理原型进行有限元数值模拟研究，分析采矿活动下陡崖及危岩应力场的变化，揭示危岩形成过程机理。模拟结果表明：采矿活动形成新的临空面，临空面附近应力方向发生偏转，开挖工作面应力集中；其对陡崖及危岩体应力场的影响主要体现在小主应力方面，压应力明显增加；并且危岩体体内大主应力变化不明显，小主应力明显增大，压应力明显减小，并且呈由临空面向内递增的趋势；危岩体后部裂缝尖端应力集中，随着开挖的推进，裂缝尖端应力呈现先减后增的趋势，当开挖达到一定深度时，与开挖深度基本呈线性关系。数值模拟结果科学地论证了采矿活动下陡崖及危岩应力场的变化特征，有助于进一步揭示矿山类危岩灾害的形成机理。%Mining activities as one of the main factors inducing the collapse disasters, this paper is simulated by the finite element with the example of Mo Ziyan No2 perilous rock to analysis the effects on stress field under the mining, and to reveal the formation mechanism of dangerous rock. The simulation results show that: Under the mining activities, a new free surface is formed, the direction of stress is deflected near the free face, and stress is significantly concentrated on the excavation surface; the effect of stress field on the steep and dangerous rock body is mainly reflected in the minor principal stress, stress significantly increased; and main stress of dangerous rock is not change significantly, the minor principal stress increases obviously, compressive stress is obviously reduced, and a trend of increasing from free surface to inside;The crack tip stress concentration in the rear of perilous rock, with the advance of the excavation, the crack tip stress appears first decrease and then increase trend, when excavation reached a certain depth, linearly with the depth of excavation. The results of numerical simulation scientifically prove the changes on stress field of steep cliffs and perilous rock under the mining activities. The results are helpful to further reveal failure mechanism of perilous rock at the mine.
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