赵东阳 祝介旺 袁博

摘要： 针对某矿区发生多起大规模滑坡、崩塌等地质灾害，对露天矿的安全和正在进行的残矿回采工作造成威胁的问题，以矿区内某矿山为研究对象，利用FLAC3D软件建立露天矿坑边坡数值分析模型，采用传统地质分析方法结合数值模拟对边坡破坏成因进行分析。结果显示，凝灰岩中发育的顺坡向节理是边坡发生滑塌的关键因素。强度折减法计算结果可知，边坡内部沿节理面形成贯通滑带，是最危险的潜在破坏面;随着时间的推移，深层节理面强度弱化，边坡可能再次发生滑塌。

关键词： 露天矿;边坡;地质灾害;滑坡;数值模拟;强度折减法

Abstract： As to the problem that there are many geological disasters such as the large scale landslide and collapse in a mining area， and the safety of open pit and the residual depesit mining are threatened， taking a mine of the mining area as the research object， the numerical analysis model of the open pit slope is built by FLAC3D software， and the traditional geological analysis method is combined with the numerical simulation to analyze the cause of slope failure. The results show that the joints along the slope direction developed in tuff are the key factor for slope landslide and collapse. According to the calculation results of the strength reduction method， a penetrating slidingzone is formed along the joint surface of the slope internal， which is the most dangerous potential failure surface. Over time， the strength of the deep joint surface is weaken， and then the slope may collapse once again.

Key words： open pit;slope;geological disaster;landslide;numerical simulation;strength reduction method

0 引 言

自20世紀50年代至今，全球露天矿开采总量约为160亿 t，其中露天开采约占80%。[1]随着露天矿开采持续向深部发展，矿山边坡的高度不断增加，但是受地质环境和用地规模的限制，矿坑的开口不能无限扩大。为开采更多的地下矿床，矿坑边坡的设计坡度越来越大，导致闭坑后的边坡存在安全隐患。据不完全统计，在我国大型露天矿山中，不稳定边坡或具有潜在滑坡危险的边坡约占边坡总量的15%～20%。[1]边坡失稳已成为露天矿山中发生频率最高、对安全生产影响最大的灾害之一。[2]

废弃矿山的治理和利用是目前的热点问题，其关键在于如何改造好、利用好废弃矿山，使其安全、环保、有效益。杜时贵等[3]提出大型露天矿山边坡岩体稳定性分级分析方法;杜时贵[4]提出大型露天矿山边坡等精度……