基于强度折减法的大型露天矿东端帮稳定性分析

拟建大型露天镍钴矿区,东西长1 670m,采深一般在300m以上,最高边坡高度超过600m。根据边坡不同位置的边坡高度、工程地质岩组分布特征、各岩组岩石质量等级、边坡面倾向与各岩体优势结构面的关系、边坡岩体完整程度等多项指标将边坡分为五个区。为研究该大型露天矿高陡边坡稳定性与开挖坡角及地下水位的关系,本文在考虑地下水位以上的岩土体饱和度变化的前提下,结合夏日哈木镍钴矿区高陡边坡实际工况,通过有限元软件ABAQUS和抗剪强度折减法模拟计算得到不同开采坡角的边坡稳定系数与地下水位的关系,从而确定出同一水位下的最小开采坡角,以及不同开采坡角下的最高地下水位。最终对本研究结果的分析得到开采坡角及地下水位对高陡边坡稳定性的重要性,并对该露天矿东端帮开挖提出了一系列建议,该研究对该露天矿的其他区域以及周围相似工程的开挖具有重要的借鉴意义。

Stability Analysis of the Eastern End of Large Open-pit Mine Based on Strength Reduction Method

The proposed open-pit mine has a length of 1670m, and the mining depth is generally over 300m, and the highest slope is over 600m, which is an important project. According to the slope height of different position, slope engineering geological petrofabric distribution characteristics, the rock groups of rock quality grade and slope surface tendency with the advantage of rock mass structure, degree of slope rock mass complete several indexes such as the relationship between the slope is divided into five areas. In order to study the relationship between the stability of the high slope and the excavation slope angle of the large open-pit mine, and the relation between its stability and the groundwater level, this paper that combined with the high and steep slope in the Xiarihamu Ni-Co mining area determine the minimum mining slope angle under the same water level and the highest groundwater level under different mining slope angles for the east end slope of the large open-pit mine on the premise of considering the change of rock mass saturation above the groundwater level. The above results are obtained based on the relationship between slope stability coefficient and groundwater level under different mining slope angles which calculated by finite element software ABAQUS and shear strength reduction method. Finally, the analysis of the results about this study obtains the importance of the mining slope angle and groundwater level to the stability of high and steep slopes, and puts forward a series of suggestions for excavating the eastern end of the large open-pit mine. At the same time, this study is of great significance for the excavation of other areas and surrounding similar projects.