金川露天矿东部采场边坡的变形破坏

SLOPE DEFORMATION FAILURE IN EASTERN STOPE OF THE JINCHUAN OPEN-PIT

矿区属高应力区.由于多次构造运动的作用,断裂十分发育,岩性复杂、岩体破碎,岩层呈陡倾层状,层间错动发育,使岩体具有软硬相间的特点. 随采深增加,边坡岩体在地应力和岩体自重应力作用下,在大爆破和采掘中长期频繁中爆影响下,边坡产生了严重变形破坏,经岩移观测和地质力学研究认为,老坑属滑移—倾倒—坍塌类型.东部采场系老坑扩延而成,由于长短轴比增大,在原变形破坏类型基础上发展,局部发生了二级次生滑坡.基于对滑坡后有一相对“平静”期的分析,在人工处理反翘陡坎弯折危石并严密监视边坡险情下,可回采部分矿石。本文提出露天矿开采及露转坑采中的一些教训,值得露采单位吸取.

The mine area is in a highly stressed zone, Being affected by multiphase tectonic movement, faults are well—developed in this area. The rock properties are complicated and the rock mass is fractured The strata are steeply inclined in shape with well—developed bedding slip and thus make the rockmass to show a weak—hard alternation in property. With the increase of mining depth, the slope rockmass became seriously deformed under the effects of geostress, rock gravrty, advance of mining and blasting. Rock movement observations and geomechanical studies suggest that the failure of the old pit is of the slidetoppling-coll-apes type. The eastern stope is formedby extending the old pit. Because the ratio between the major and minor axes increased, secondary landslide took place locally on the basis of the original deformation failure. Based on the understanding that there is a relatively stable stable period after landslides, it is considered that a part of the ore can be extracted under the prerequisite of removing manually the dangerous stones in advance and monitoring closely the deformatlon of the slope This paper introduces some lessons about open-pit mining and open-pit turning into underground mining. It is necessary for open-pit mining to pay attention to them.