裂隙岩体质量三维精细分级S-RMRmbi方法及可视化

传统岩体质量分级方法级别较少,其评分标准常呈阶梯状,应用于裂隙岩体质量评价时,其精度无法满足岩体质量出现复杂多变情况时的评级要求,使得同级别岩体质量可能出现显著差异,因此有必要将岩体质量级别做进一步精细分级处理,并为评价岩体工程稳定性和制定支护方案提供依据。基于前期开展的岩体质量RMR_mbi分级方法和结构均质区三维分显研究工作,以广西铜坑矿锌多金属矿体3^#矿块为试验区,进行RMR_mbi质量评级;结合综合模糊判别理论,提出岩体质量精细分级S-RMR_mbi方法,对试验区分级结果做进一步细化;并以均质区三维分显模型为载体,借助3DMine可视化功能,构建岩体质量精细分级可视化模型;从定性以及定量两方面对RMR_mbi和S-RMR_mbi法进行对比分析后,进一步提出与精细分级后的岩体相对应的支护方案。研究结果表明:(1)质量5级分档对凸显裂隙岩体质量层次性效果不够理想,基于综合模糊判别理论的岩体质量精细分级S-RMR_mbi方法有效细化了岩体质量分级结果;(2)赋有S-RMR_mbi分级属性值的各均质区及重组模型展示了岩体质量的空间分布特征;(3)S-RMR_mbi和RMR_mbi两分级结果模型显示其岩体质量分布状况大体一致,基于相似度的两方法λ12值为0.999 2,验证了S-RMR_mbi分级方法的合理性;(4)精细化分级后的岩体可采取更为细致、有效的支护手段。研究成果对于提升裂隙岩体质量评价精度与制定具体施工方案具有重要的指导作用。

Three-dimensional Sub-classification for Jointed Rock Mass Quality (S-RMRmbi) Based on Comprehensive Fuzzy Identifying Theory

Traditional rock mass quality classification systems always have fewer ratings, and their rating criterions are often lump, which lead to significant differences in the same rating. Therefore, it is necessary to refinedly classify the rock mass qualities. And the classification could also provides a basis for evaluating the stability of rock mass engineering and formulating support scheme. Based on the author's previous studies, i.e., improved Rock Mass Rating system based on modified blockiness index (RMR_mbi) and the three-dimensional visualization of statistically homogeneous structural domains of rock masses, the No. 3 block of the Zn polymetallic orebody in Tongkeng Mine (China) were selected as the test area. A task of RMR_mbi was conducted combining with comprehensive fuzzy identifying theory, and subsequently, the sub-classification of RMR_mbi (S-RMR_mbi) was developed to further refine the classification results. Based on the 3D visualization models of the homogeneous domains, the visualized models of the S-RMR_mbi classification results were constructed with the visualization function in 3DMine. After comparing and analyzing RMRmbi and S-RMRmbi methods qualitatively and quantitatively, the supporting scheme corresponding to the fine-graded rock mass was put forward, and the results show that: (i) The RMR_mbi system with five levels is not capable of highlighting the differences in rock mass qualities, and the S-RMR_mbi system can effectively refine the rock mass qualities; (ii) Homogeneous domains and recombination models with S-RMR_mbi values show the spatial distributions of rock masses with various qualities; (iii) The models highlighted with S-RMR_mbi and RMR_mbi values show that the quality distributions of rock masses are fairly identical, and based on the similarity degree, the λ₁₂ (similarity degree) of the two systems is 0.9992, indicating that the rationality of the S-RMR_mbi system is supported; and (iv) After refinedly classification, the rock mass can be adopted more detailed and effective support measures. This study may provide a guidance for improving the accuracy of rock mass evaluation and determining the specific engineering designs.