南芬露天铁矿高陡边坡失稳与降雨相关性研究

Research on correlations between slope stability and rainfall of high steep slope on Nanfen open-pit iron ore

在露天矿开采过程中,高陡边坡的稳定性日益成为威胁其安全生产的一大难题。以辽宁南芬露天铁矿为工程背景,结合其下帮高陡边坡工程地质与水文地质条件,发现雨季降雨是高陡边坡滑坡的重要原因,利用边坡滑动监测系统与降雨量实时监测系统得到滑坡与同时期降雨量监测数据,进行降雨与边坡局部失稳滑坡的相关性分析,发现降雨量大于100 mm的大暴雨与滑坡具有很好的相关性,暴雨及以上强度的降雨是诱发下帮边坡滑坡的重要因素。利用SEEP/W有限元软件模拟大暴雨入渗条件下边坡岩体渗流场变化全过程,计算不同渗流时刻的边坡稳定性系数与边坡应力应变情况,验证统计分析的可靠性并揭示降雨对边坡稳定性影响的机制,同时发现在大暴雨过后,滑坡一般具有24 h左右的滞后性,并提出南芬露天矿山岩质高陡边坡水文灾害治理的有效措施。研究成果可为类似高陡边坡工程提供有意义的参考。

The stability of high steep slope has become a major safety concem in the process of open pit mining in NanFen open-air iron ore. According to the results of engineering geological investigation and the analysis of geologic characteristics and hydrogeology conditions, It found that rainfall in rainy season is an important cause of landslide, the monitoring data of slope stability and rainfall at the same period are analyzed, It is concluded that when the rainfall is more than 100 mm, the slope failure is closely related to the rainfall. Finite element simulation software SEEP/W is used to simulate all the stages of rainfall infiltration of high steep slope, the slope safety factor at the different seepage moment is calculated, this results not only prove the accuracy of statistical analysis but also reveal the mechanical mechanism of slope instability, meanwhile it found the landslide has a lag of about 24 hours in heavy rain, the effective treatment method for high steep slope hydrology disaster of NanFen open-air iron ore is put forward. The results of this study may be useful for the protection of the same projects.