基于组合赋权-未确知测度理论的地铁隧道围岩质量评价

为了合理确定地铁隧道围岩质量等级,引入未确知测度理论建立了地铁隧道围岩质量评价模型,并选取岩石饱和单轴抗压强度、变形模量、质量指标、地下水、岩体抗剪强度、结构面摩擦系数等6项指标作为未确知测度模型的判别指标。以杭州地铁1号线为例,构造各指标的未确知测度函数,同时利用粗糙集优化层次分析法和改进的熵值法确定各指标的组合权重,依照置信度识别准则对围岩质量等级进行识别,并对其危险性程度进行排序,最后得出围岩质量分级的评价结果。将围岩质量分级的评价结果与现场评价和云模型评价结果进行对比分析,评价结果基本符合实际情况。研究表明,该方法评价过程合理、结果可靠,为地铁隧道围岩质量评价提供了一种新思维。

Evaluation of Metro Tunnel Based on Combined Weighting-Unascertained Measurement Theory

In order to rationally determine the quality grade of metro tunnel surrounding rock, a surrounding rock evaluation model is established on the basis of uncertainty measurement theory. Six main factors including uniaxial compressive strength, deformation modulus, rock quality designation, groundwater condition, rock shear strength, and friction coefficient of structural plane are selected to act as the indexes of the uncertain measure model. With reference to Hangzhou Metro Line 1, the unascertained measure function of each index is constructed. The combination weights of all indexes are calculated by the modified analytic hierarchy process and the improved entropy theory. The quality of the surrounding rock is identified based on credible recognition criteria, and then the order of hazard is defined. The quality grade of subway tunnel surrounding rock is obtained by the model. Finally, the results of comparative analysis are compared with those of Cloud model and on-site evaluation, and they are basically consistent with the actual situations. The research shows that the method is reasonable and reliable, and can provide a new thinking for the quality evaluation of metro tunnels.