关键块体失稳表征系数与岩坡稳定性评价
Instability characterization coefficient of key block and evaluation of rock slope stability

建立了一种关键块体判别方法,实现了岩坡整体稳定性的准定量化评价; 综合考虑关键块体的几何特性和受力特征,定义了关键块体失稳表征系数; 利用团队自主研发的GeoSMA-3D平台,开发出基于失稳表征系数的关键块体搜索模块,可视化了包括块体搜索、可移动块体判断、关键块体确定、块体失稳和滑落的关键块体失稳全过程; 引入层次分析法,利用关键块体失稳表征系数计算出各关键块体的权重,应用关键块体的安全系数及其计算权重,联合确定了岩坡稳定性表征安全系数,应用关键块体信息定量表征了岩坡的整体稳定性; 提出了一种考虑岩体结构面和关键块体的岩坡稳定性评价方法; 以辽宁省建昌岩坡工程为例,应用该方法进行了关键块体的确定和可视化再现,判断了岩坡的整体稳定性,并与数值流形元法(NMM)的模拟结果和现场实测结果进行了对比分析,以验证应用关键块体表征岩坡稳定性评价方法的可行性和适用性。研究结果表明:控制该岩坡稳定性的关键块体有6个,基于所提出方法计算的岩坡稳定性表征安全系数为0.566 9(不稳定岩坡),与现场监测数据所得结果的相对误差为7.066%; 在NMM模拟结果中,采用安全系数法确定的最不利关键块体的滑落没有引起岩坡失稳,而基于所提出方法确定的最不利关键块体的滑落导致了岩坡的整体失稳,因此,同时考虑关键块体体积和安全系数2个因素的岩坡稳定性评价方法更合理,基于层次分析法,应用关键块体信息表征的岩坡稳定性与工程实际吻合。
A key block determination method was established to realize the quasi-quantitative evaluation of rock slope stability. The concept of instability characterization coefficient of key block was defined by comprehensively considering the geometric characteristics and mechanical properties of key blocks. The program GeoSMA-3D developed by the authors' team was used to develop the search module for key blocks based on the instability characterization coefficient. The entire instability process of key blocks, including the search for blocks, judgment of moveable blocks, determination of key blocks, slide and instability of blocks was visualized. Using the instability characterization coefficient of key blocks, the weight of each key block was calculated through the introduction of the analytic hierarchy process. The characterization safety factor of rock slope stability was determined through the combination of the safety factors and weights of key blocks. Key block information was used to characterize rock slope stability, and a method for evaluating the rock slope stability was proposed by considering rock structural planes and key blocks. Taking the Jianchang Rock Slope in Liaoning Province as an example, the determination and visualization of key blocks were carried out by using the proposed method to examine the rock slope stability. The results were compared with those of the numerical manifold method(NMM)and the on-site monitoring data to verify the applicability and feasibility of the proposed method. Research result shows that there are six controlling key blocks for the rock slope stability. The characterization safety factor of rock slope stability calculated through the proposed method is 0.566 9(an unstable rock slope). The relative difference between the calculated results and those from on-site monitoring is 7.066%. In the simulation results from NNM, the slippage of the most unfavorable key block determined by the safety factor method