基于地质安全评价的废弃矿山高陡边坡生态修复技术研究
Research on ecological restoration technology of high-steep slopes of abandoned mines based on geological safety evaluation
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摘要: 新一轮找矿突破战略行动需要关注生态环境保护,废弃露天矿山生态修复则是矿地综合利用、生态环境保护的重要举措,其中高陡边坡修复是废弃矿山生态修复的重点与难点。为此,选择浙江省兰溪市灵洞乡洞源村废弃露天矿山开展了生态修复技术示范研究,在实地勘察、工程地质测绘与工程钻探的基础上,基于有限元方法,对边坡进行安全性数值分析,进而对高陡边坡实施生态修复。数值分析表明:边坡随着降雨的进行,其安全系数从1.458降至0.851,存在安全隐患;高陡边坡生态修复必须辅以削坡降低斜坡坡度、在边坡前缘实施挡土墙等工程手段才能达到安全性要求;合理排水可大大降低水对边坡安全性的影响,增强边坡的稳定性。经过生态修复设计后,暴雨条件下边坡安全系数显著提高且基本保持在1.7左右,达到了安全性的设计要求。该技术示范可为其他废弃矿山生态修复提供参考。Abstract: The new round of national strategic mineral prospecting requires to pay attention to ecological protection. The ecological restoration of abandoned open-pits is an important step in the comprehensive use of mine land and ecological environmental protection, among which the restoration of high-steep slopes is the focus and difficulty. To this end, an ecological restoration technology pilot study was carried out at the abandoned open pit mine in Dongyuan Village, Lingdong Township, Lanxi City, Zhejiang Province. Through field surveys, engineering geological mapping and engineering drilling, a numerical analysis of slope safety based on the finite element method was conducted for the ecological restoration of high-steep slopes. The analysis results show that the safety factor of the slope reduced from 1.458 to 0.851 with the rainfall, which makes it a safety hazard. Ecological restoration of high-steep slopes shall be complemented by engineering measures, including slope cutting to reduce the slope gradient and the construction of retaining walls at the leading edge of the slope, to meet safety requirements; Adequate drainage can greatly reduce the impact of water on slope safety and improve slope stability. With the ecological restoration design, the safety factor of the slope under heavy rainfall conditions significantly increased and almost maintained at around 1.7, which meets the safety design requirements. This technology demonstration can provide a reference for the ecological restoration of other abandoned mines.