基于爆破损伤的露天矿边坡稳定性的灾变分析

Stability Analysis of Open-pit Slope Based on Blasting Damage with Catastrophe Theory

基于爆破震动影响下露天矿岩质边坡滑动趋势面介质的损伤弱化效应,建立了爆破荷载、后缘裂隙静水压力及滑动趋势面扬压力共同作用下的尖点突变模型,并根据导出的临界爆破药量的表达式给出了边坡失稳的判据条件.以鞍千矿业有限公司许东沟采场西帮的一处滑坡为例,利用建立的二维简化模型和导出的失稳判据对边坡在多次爆破作业影响下的稳定性进行了分析,得到了稳定性随爆破次数累积的变化规律.结果表明:边坡失稳的可能性随爆破次数的增加呈现递增的趋势,同时也说明了边坡失稳的发生通常不是仅由一次爆破作业造成的,而是由于多次爆破作用的累积效应所致.通过对比4次爆破作业的临界药量和实际药量,验证了利用导出的失稳判据评价露天矿边坡的稳定情况是合理可行的,对爆破开挖设计中实际药量的选择有一定的指导意义.

Based on the damage weakening effect of the sliding-trend surface of the rock slope in open-pit mine under the influence of blasting vibration,cusp catastrophe model of the rock slope under open blasting,static water pressure of splay fracture and flotage of the sliding-trend face are built and the criterion for the slope instability is proposed in this paper according to the derived expression of the critical explosive dosage.The stability of the slope under the influence of multiple blasting is analyzed by using the established two-dimensional simplified model and the derived criterion and the variation of stability with the blasting times is obtained according to the west slope of Xudonggou Mine of Anqian Mining Co.Ltd.The results show that the possibility of slope instability increases with the increase of blasting times and the occurrence of slope instability is usually caused not only by a single blasting operation,but by the cumulative effect of repeated blasting.Comparing the critical dosage and actual dosage of the four blasting operations,it is verified that the evaluation of the stability of the open-pit slope by using the derived instability criterion is reasonable and feasible,and it has a certain guiding significance for the selection of the actual dosage in the blasting excavation design.