岩性劣化对露天矿山边坡稳定性的响应规律

针对岩性条件劣化导致边坡稳定性下降的问题,以某露天矿山边坡为研究对象，运用SIR-20型地质雷达探测矿山滑坡体内部缺陷,并结合Slide软件模拟分析了不同岩性条件下边坡稳定性的变化规律。结果表明：软弱夹层、降雨入渗和爆破动荷载等内外因共同作用造成边坡岩性劣化，进而导致边坡后期出现滑移失稳；黏聚力c值降低是岩性劣化过程中的主要力学表现，安全系数与c值呈部分抛物线关系，且c值降为50 kPa是边坡特殊工况的失稳临界值。在综合分析矿山运行特征和岩性劣化条件基础上，提出通过减小上部第四系台阶坡面角和最终边坡角提高其永久稳定性的建议，安全系数经验证符合要求。研究结果可为矿山后期安全开采和边坡控制参数取值提供重要依据。

Response Law of Lithology Deterioration on Slope Stability of Open-pit Mines

In view of the fact that lithology deterioration condition leads to the decline of slope stability，and with a slope of open-pit mine as the research object，the internal defects of landslide were detected by SIR-20 geological radar，and the change law of slope stability under the condition of different lithology was analyzed with Slide software.Results showed that：slope lithology deterioration is caused by the interaction of weak interlayer，the rainfall infiltration and the blasting dynamic load，which lead to the slope sliding and instability in the late; c value reduction is the main mechanical performance in the process of lithology deterioration; Safety factor and c value showed as a partial parabola relationship，and the reduced c value 50 kPa is the critical value of slope instability under special working conditions.According to a comprehensive analysis of mine operating characteristics and the lithology deterioration condition，a proposal to improve its permanent stability by decreasing the upper quaternary bench slope angle and final slope angle is put forward.It is proven that the safety factor could meet the requirements.The results provide an important basis for safety mining and determining slope control parameters in the late.