高陡岩质边坡“面—点—面”稳定性综合评价方法——以安太堡露天矿为例

"Plane-Point-Plane"Stability Integrated Evaluation Method of High and Steep Rock Slope:A Case Study of Antaibao Open-pit Mine

为了能够有效识别边坡危险区和准确判断边坡稳定状态,提出了一种基于模糊综合评价法、MSARMA法和FLAC^(3D)的“面—点—面”边坡综合评价方法。首先根据现场边坡岩体的组成和结构特征,总结出滑坡成灾因子,并根据滑坡体特征和采空区时空分布特征划分出离散型和连续型变量的赋值标准;然后,基于模糊数学综合评判原理,对多因素影响域内的高陡边帮稳定性进行综合评价,确定出不稳定区、较不稳定区、较稳定区和稳定区空间区划;最后以不稳定区域的边坡潜在滑动面为计算模型,采用MSARMA方法进行边坡影响因子的敏感性分析,确定出敏感性因子,并用FLAC^(3D)有限差分法进行数值模拟分析。以安太堡露天煤矿为例,划分了其不稳定区域,得出了在渗流和震动等敏感因子下的位移场演变规律。结果表明:天然工况下,边坡X、Y方向最大位移为30cm和41cm;渗流工况下,西北帮边坡X、Y方向最大位移分别为45cm和70cm;在地震作用下,北边帮和西边帮底部点的位移变化较小,顶部点的位移较大。在上述分析的基础上,根据数值模拟分析结果提出了不稳定区域边坡加固及监测的设计方案,确保了边坡的整体稳定性。所提出的边坡综合评价方法可为类似高陡岩质边坡稳定性分析提供参考。

In order to effectively identify the danger area of slope and accurately judge the stability state of slope,a set of"face-point-surface"slope comprehensive evaluation method based on fuzzy comprehensive evaluation method,MSARMA method and FLAC3D was proposed.Firstly,according to the composition and structural characteristics of the on-site slope rock mass,disaster factors were summarized,while assignment criteria for discrete and continuous variables were divided based on the landslide body characteristics and spatiotemporal distribution.Following,based on the comprehensive evaluation principle of fuzzy mathematics,the high and steep side stability in the multi-factor influence regions was comprehensively evaluated,while the spatial division of the unstable region was determined.Finally,the slope potential slip surface in the unstable zone of the western side was utilized as the calculation model object,while the sensitivity analysis of the slope impact factor was conducted through the MSARMA method,and the sensitivity factors were determined.The FLAC3D finite difference method was utilized for numerical simulation analysis,and the conclusion was drawn.Taking Antaibao Open-pit Coal Mine as an example,its unstable area was divided and the evolution law of displacement field under sensitive factors such as seepage and vibration was ob-tained.The results showed that under natural conditions,the maximum displacements in X and Y directions of the slope are 30 cm and 41 cm,while under seepage conditions,the maximum displacements in X and Y directions of the northwest slope are 45 cm and 70 cm,respectively.Under the action of earthquake,the displacements at the bottom of the north slope and the west slope change little,while the displacement at the top is larger.Based on the above results of numerical simulation,the design scheme of slope reinforcement and monitoring in unstable region was proposed to ensure the stability of the whole slope.The in-tegrated evaluation method could provide reference for the stability analysis of similar high and steep rock slopes.