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为了给布伦口-公格尔水电站地下洞室某标段围岩稳定性分析的参数选取提供可靠的理论依据,综合考虑岩体参数的空间变异性,针对常规敏感性分析方法所存在的不足,运用三维离散元计算程序,提出了基于围岩力学参数概率分布模型的变形敏感性灰关联分析方法。该方法以岩体密度ρ、弹性模量E、泊松比μ、黏聚力c、内摩擦角φ及节理内摩擦角φj等6个围岩力学参数作为因素序列,拱顶下沉量作为目标序列,分析影响因素在整个定义区间内的变化对围岩拱顶下沉的敏感程度。结果表明:密度是最敏感因素,其次是弹性模量、黏聚力和泊松比,而内摩擦角以及节理内摩擦角敏感性最小。最后,将常规灰关联敏感性分析与该方法计算结果进行对比,结果表明:除密度、内摩擦角和节理内摩擦角一致外,其余参数敏感性均与结论不一致。因此,文中方法在考虑实际参数概率分布的基础上能够更加准确、合理地对参数进行综合评价。
In order to provide a reliable theoretical basis for the parameter selection of surrounding rock stability analysis of a section of Beringkou-Gong’er Hydroelectric Station underground cavern, taking into account the spatial variability of rock mass parameters, in view of the shortcomings of conventional sensitivity analysis methods , A deformation sensitive gray correlation analysis method based on the probabilistic distribution model of mechanical parameters of surrounding rock is proposed by using 3D discrete element calculation program. The rock mass density ρ, elastic modulus E, Poisson’s ratio μ, cohesion c, internal friction angle φ and joint internal friction angle φj six mechanical parameters as a sequence of factors, the amount of dome subsidence as Target sequence, analysis of the impact of changes in the entire definition of the range of the surrounding rock vault sinking sensitivity. The results show that density is the most sensitive factor, followed by elastic modulus, cohesion and Poisson’s ratio, while the internal friction angle and the joint internal friction angle sensitivity is the least. Finally, the correlation between the conventional gray correlation sensitivity and the calculated results is compared. The results show that the sensitivity of other parameters except the density, internal friction angle and joint internal friction angle are inconsistent with the conclusion. Therefore, based on the probability distribution of actual parameters, the proposed method can evaluate the parameters more accurately and reasonably.