考虑闭坑后抽水蓄能的露天矿边坡稳定性分析

Stability analysis of open-pit mine slope considering pumped-storage after mine closure

由于经济、环境及相关政策影响,我国废弃矿井数量与日俱增,将关停的废弃露天矿重新设计改造成抽水蓄能电站可以提高储能能力、调节地区电网负荷、提高电力系统的稳定性和可靠性,并推动废弃矿区生态修复和资源型城市转型。以抚顺市西露天矿作为研究对象,通过对我国废弃矿井及新能源分布现状的阐释,结合辽宁省电网调峰现状,论证西露天矿抽水蓄能电站建设的必要性;根据西露天矿相关工程背景及地质勘探结果,对西露天矿抽水蓄能电站上下水库选址设计和输水系统工程布置进行研究;抽水蓄能电站的建设会改变废弃矿坑的水位,从而影响矿坑的边坡稳定性。构建西露天矿下水库剖面模型并将其导入Geo-studio软件中,采用极限平衡法结合稳态渗流场分析−395 m、−350 m、−250 m水位下考虑水力效应的矿坑边坡稳定性。研究结果表明:抚顺市西露天矿抽水蓄能电站建设在技术上可行,在经济上合理,可以很好地满足辽宁省电网调峰调频需求,缓解电网运行压力大等问题;拟定西露天矿抽水蓄能电站装机容量为1200 MW,满发小时数为5 h,矿坑东侧区域为下水库,南花园湖为上水库,且上下水库的调节库容大致相等。输水线路布置在西露天矿坑南侧的花岗片麻岩内部;西露天矿坑边坡潜在的滑移风险可能发生在特定水位下的几个区域。为保证抽水蓄能电站投入使用后的库岸边坡稳定性,还需要采取进一步的防渗加固工作。

Due to economic,environmental,and related policy factors,the number of abandoned mines in China has been increasing.Repurposing these abandoned open-pit mines as pumped-storage power stations can enhance energy storage capacity,regulate regional power grid loads,improve the stability and reliability of the power system,and promote ecological restoration of abandoned mine areas and the transformation of resource-based cities.This paper focuses on the West Open-Pit Mine in Fushun City as the research subject.By analyzing the distribution of abandoned mines and new energy sources in China and considering the peak regulation status of the power grid in Liaoning Province,demonstrating the impact of constructing a pumped-storage power station in the West Open-Pit Mine.Based on the relevant engineering background and geological exploration results of the West Open-Pit Mine,providing explanations for the site selection and design of the upper and lower reservoirs of the pumpedstorage power station,as well as the layout of the water conveyance system.The construction of the pumped-storage power station will alter the water level in the abandoned mine pit,affecting the stability of its slopes.Constructing a cross-sectional model of the lower reservoir in the West Open-Pit Mine and importing it into Geo-studio software.Using the limit equilibrium method combined with steady-state seepage field to analysis the slope stability at water levels of−395 m、−350 m、−250 m.The results indicate the following the construction of the West Open-Pit Mine pumped-storage power station is technically feasible and economically reasonable.It can effectively meet the peak regulation and frequency modulation requirements of the power grid in Liaoning Province,alleviating operational pressures in the region.The proposed installed capacity for the West Open-Pit Mine pumped-storage power station is 1200 MW,with a full-load operating time of 5 hours.The eastern area of the pit serves as the lower reservoir,while Nanhuayuan Lake functions as the upper reservoir,with approximately equal regulating capacities.Potential sliding risks in the West Open-Pit Mine slopes may occur at specific water levels.To ensure the stability of reservoir embankments after the pumped-storage power station is operational,further anti-seepage reinforcement measures are necessary.