某矿山露天采场北帮边坡稳定性分析

Stability Analysis of the Northern Slope in an Open-pit Mine

某矿山露天采场边坡自开采以来,滑坡、崩塌、倾倒和沉降等不同规模的地质灾害频发,亟需对边坡稳定性进行预测并采取合理防护措施。该文以该矿山采场北帮边坡为例,通过结合已揭露地表踏勘、无人机近景拍照和离散元数值模拟等手段对露天采坑北帮边坡开挖后的稳定性进行推测和分析计算。研究表明:1)采场坡体由于受结构面网络切割,呈现多种复合破坏模式,如平面滑动、楔形体滑动和倾倒型破坏等破坏模式;2)北帮边坡软硬相间、反倾层状结构和坡脚应力集中等因素共同作用,将导致北帮边坡发生大规模弯曲—倾倒变形。研究进一步揭示了北帮边坡变形失稳机理,可在保障露天采坑安全运营的条件下产生更大的经济效益。

Since the slop of the open-pit mine has been mined,geological disasters of different scales,such as landslides,collapses,dumps and settlements occur frequently.It is urgent to predict the slope stability and take reasonable protective measures.Taking the northern slope of the mining pit as an example,the stability of the northern slope after excavation is predicted and calculated by means of surface exploration,UAV close-up photography and discrete element numerical simulation in this paper.The research shows that:1)The mining slope body,due to being cut by the network of structural planes,presents a variety of composite damage modes,such as plane sliding,wedge sliding and dumping-type damage and other damage modes.2)The northern slope is affected by the interaction of soft and hard,antiinclined layered structure and stress concentration at the slope foot,which will lead to large-scale bending-dumping deformation of the northern slope.The study further reveals the deformation and instability mechanism of the northern slope,which can produce greater economic benefits under the condition of ensuring the safe operation of open-pit.