地下工程爆破对危岩稳定性的影响

Impact study on stability of unstable rock under underground construction blasting

根据爆破峰值速度衰减规律及危岩体主控结构面的假定,通过欧拉方程确定作用于危岩体峰值爆破荷载,并对峰值荷载进行修正得到时程爆破惯性力,建立了3类危岩体动力物理模型及计算模型,结合极限平衡方法得到3类危岩体动力稳定系数计算方法,选取最小的稳定性系数作为整个危岩体的动力稳定性系数,最终给出了3类危岩动力稳定性评价方法。以重庆市万州区太白危岩体为例,选取5个代表性危岩体进行动力稳定性计算,结果表明,3类危岩体动力稳定系数计算方法能较好地评价和反映危岩体的动力性态。

On the basis of the peak velocity decay law of blasting and the assumption of unstable rock dominant fissure, and using Euler equations to work out the load of peak value blasting which acts on unstable rocks, and correcting peak force, it figured out the time history of blasting inertia force. Dy- namic physical model and calculation model for three kinds of unstable rock were set up. The calcula- tion method of stability coefficient with three kinds of unstable rock was given by combining with the limit equilibrium method. Within the scope of blasting time, it takes the minimal stability coefficient as the dynamic stability coefficient of the whole unstable rock, and establishes three kinds of dynamic evaluation method of unstable rock. Taking unstable rocks in Taibaiyan of Wanzhou in Chongqing as an example, five typical unstable rocks were chose to work out the calculation of dynamic stability co- efficient. The calculation result can well evaluate and reflect the dynamic characteristics of unstable rock blocks by the calculation method for dynamic stability coefficient of the three kinds of unstable rock blocks.