山岭隧道坍塌风险评价的熵权–集对分析模型及工程应用

Entropy Weight-set Pair Analysis Model of Collapse Risk Assessment in Mountain Tunnels and Its Engineering Application

针对山岭隧道坍塌风险评价的多指标性和不确定性的特点,将集对分析法与信息熵理论相结合,应用于山岭隧道坍塌风险评价。首先,综合考虑隧道坍塌的孕险环境和致险因子,选取围岩级别、地下水、不良地质、初期支护刚度、开挖方法、施工技术水平和施工管理水平等主要影响因素作为评价指标。其次,将集对分析法引入到隧道坍塌风险评价中,从同、异、反的角度分析隧道稳定-失稳的确定-不确定性问题,并构建评价指标与分级标准的集对体系。然后,将坍塌风险评价指标划分为效益型指标和成本型指标两大类,基于集对分析法计算各指标的单指标联系度。同时,引入信息熵理论确定评价指标客观权重,并将其耦合到评价指标的单指标联系度中,构建隧道坍塌风险评价的熵权-集对综合联系度评价模型。最后,利用置信度识别准则判定最终坍塌风险等级。以宾房2号隧道为例,对右幅隧道K31+500~K31+660浅埋段进行了重点分析,评估结果与现场实际情况较吻合。结果表明:基于集对分析法建立隧道稳定-失稳的确定-不确定性关系,较好地解决了山岭隧道坍塌风险等级评价中多指标性和不确定性;利用修正熵权法确定指标权重,减少了人为因素影响;引入置信度识别准则判别隧道坍塌风险,较好地弥补了最大隶属度原则取大运算造成评价结果失真的缺陷。该方法评价过程合理,结果可靠,是一种有效的坍塌风险评价方法,为山岭隧道坍塌风险评价提供一条新的研究思路。

Considering the characteristics of multi-index,fuzziness,and uncertainty of collapse in mountain tunnels,the set pair analysis(SPA)method and information entropy theory were combined and applied for risk assessment of collapse.Firstly,the risk environment and risk factors of tunnel collapse were considered,and the main influencing factors,such as surrounding rock grade,groundwater,unfavorable geology,initial support stiffness,excavation method,construction technology level,and construction management level,were selected as evaluation indices.Second,the SPA method was introduced into the tunnel collapse risk assessment,and the certainty-uncertainty problem of tunnel stability-in-stability was analyzed from the perspectives of identity,discrepancy,and contrary,and a set pair system of evaluation indexes and classification standards was constructed.Then,the evaluation indices of collapse were divided into two main types:benefit type and cost type indices.Based on SPA,the single index connection degrees of evaluation indices were calculated.At the same time,the information entropy theory was introduced to determine the objective weight of the evaluation index,and it was coupled to the single index connection degree of the evaluation index,and the entropy weight-set pair comprehensive connection degree evaluation model of tunnel collapse risk assessment was constructed.Finally,the credible degree recognition criterion was used to determine the risk level collapse.Taking Binfang 2#tunnel as an example,the shallow-buried section of the right tunnel K31+500~K31+660 was emphatically analyzed.The results showed that the determination uncertainty of tunnel stabil-ity instability based on the set pair analysis method could better solve the multi-index and uncertainty in the risk assessment of mountain tunnel collapse.The modified entropy weight method was used to determine the index weight,which reduced the influence of human factors;The con-fidence recognition criterion was introduced to identify the risk of tunnel collapse,which made up for the distortion of evaluation results caused by the maximum membership principle.The evaluation process of this method is reasonable,and the results are reliable.It is an effective collapse risk evaluation method and provides a new research idea for the collapse risk evaluation of mountain tunnel.