基于MSR300雷达监测的凹山采场降雨条件下的边坡变形及滑坡

降雨是诱发滑坡的主要因素之一,尤其在暴雨条件下,更易激发滑坡.随着南帮边坡开采高陡化,滑坡发生频繁.为研究降雨条件下南山矿凹山采场南帮边坡稳定性特征,采用MSR300型雷达对边坡进行了连续4 a的实时稳定性监测,基于采集到的采场降雨数据和边坡滑移数据,分析了降雨量和降雨强度与边坡变形规律,对凹山采场滑坡各阶段进行了划分,建立了凹山采场边坡失稳模型和预警阈值.结果表明:凹山采场变形与降雨量呈正相关,服从幂函数规律;边坡变形速度曲线与降雨强度有良好的一致性,滑坡一般发生在最大降雨强度之后;滑坡阶段主要包括初始变形阶段,稳定变形阶段和加速变形阶段;报警阈值分别为:6 h时序内,位移阈值为20 mm,速度阈值1.5 mm·h^-1;12 h时序内,位移阈值为30 mm,速度阈值为2.5 mm·h^-1.凹山采场滑坡曲线与岩土体非稳定蠕变曲线具有较高的相似性,位移曲线出现了

Investigation of deformation and failure in washan slope considering rainfall conditions based on MSR300 radar monitoring

Rainfall, especially in rainstorm conditions, is one of the major factors considered in simulating landslides. Landslides often occur on the southern slope of Washan stope in Nanshan iron mine as the slope has increased in height and steepness. To determine the influence of rainfall on slope stability, the southern slope of Washan stope was monitored dynamically by MSR300 radar system for four years in real time. Based on data on rainfall and slope deformation, the slope deformation law between rainfall and rainfall intensity was analyzed. The stages of a landslide were classified by taking a landslide on the southern slope of Washan stope as an example. The deformation displacement and speed of this slope as well as the duration subjected to heavy rainfall were generalized. Then, the instability model and warning threshold were established. The results show that the slope deformation is positively correlated with rainfall in accordance with the power function. The slope deformation velocity is in good agreement with the rainfall intensity. Furthermore, the landslide generally occurs after maximum rainfall intensity. The landslide stages were classified into three, namely, initial deformation, stable deformation, and accelerated deformation. The warning threshold of displacement was 20 mm within 6 h and 30 mm within 12 h. The speed threshold was 1.5 mm·h-1 within 6 h and 2.5 mm·h-1 within 12 h. The landslide curve on the stope was highly similar to geotechnical non-steady creep curve. "Sharp convex"and"step jump"phenomena occurred on the curve, which could cause slope slide particularly at the inflection point of the slope deformation displacement curve and convex point of the corresponding velocity curve. The research results can provide a scientific basis and reference for slope stability monitoring and failure mechanism of similar mines.