软岩隧道塌方事故致灾因素耦合分析*

为减少专家主观判断对软岩隧道塌方事故评估的影响，提出1种从事故出发逆推分析事故致灾因素耦合机制的方法。基于142个隧道施工塌方事故案例，系统总结隧道塌方事故致灾因素，对塌方事故的致灾因素出现频率进行排序；从致灾因素之间关联耦合关系出发，结合隧道施工塌方事故的多因素耦合致灾机理，研究隧道塌方事故产生过程的多因素耦合路径和耦合过程；采用N-K耦合模型开展隧道塌方事故多因素耦合路径下的耦合关联值评估，并对耦合关联值进行排序从而找到控制塌方事故发生的致灾因素组合。结果表明:除4个主要致灾因素的全耦合外，围岩岩性-降雨-地下水的耦合关联值是洞身段中最大值，为17.79%，围岩岩性-偏压-地下水的耦合关联值是洞口段中最大值，为24.02%；洞身段的围岩岩性-地下水因素和洞口段的围岩岩性-偏压因素分别对耦合关联值大小起决定影响；耦合关联值不具备叠加效应，2因素耦合关联值可能比3因素耦合关联值更大。研究结果可为提高隧道事故分析与安全防控提供科学依据。

Coupling analysis on accident-causing factors of collapse accidents in soft rock tunnel

In order to reduce the influence of the subjective judgment of experts on the evaluation of collapse accident in the soft rock tunnel,a method for inversely analyzing the coupling mechanism of accident-causing factors from the accident was proposed.Based on 142 cases of tunnel construction collapse accident,the accident-causing factors of tunnel collapse accidents were systematically summarized,and the occurrence frequencies of collapse accident-causing factors were sorted.Starting from the correlation and coupling relationship between the accident-causing factors,combined with the multi-factor coupling accident-causing mechanism of tunnel construction collapse accidents,the multi-factor coupling path and coupling process of the tunnel collapse accident were studied.The N-K coupling model was used to evaluate the coupling correlation value under the multi-factor coupling path of the tunnel collapse accident,and the coupling correlation values were sorted to find the combination of accident-causing factors controlling the occurrence of collapse accidents.The results showed that in addition to the full coupling of four main accident-causing factors,the coupling correlation value of surrounding rock lithology-rainfall-groundwater at the tunnel body section was the largest as 17.79%,and the coupling correlation value of surrounding rock lithology-bias pressure-groundwater at the entrance section was the largest as 24.02%.The surrounding rock lithology-groundwater factor of the tunnel body section and the surrounding rock lithology-bias pressure factor of the entrance section respectively played the decisive influence on the coupling correlation value.Moreover,the coupling correlation value did not have the superposition effect,and the two-factor coupling correlation value might be greater than the three-factor coupling correlation value.The research results provide important scientific basis for improving the tunnel accident analysis and safety prevention and control.