山岭隧道施工中塌方风险评估模型研究及应用

Study on risk assessment model of collapse during construction of mountain tunnel and its application

为评估隧道施工中塌方风险,以确定其可能性及严重程度作为2条主线。由文献调研并结合待评估隧道风险特征、施工现状、工程概况等建立塌方可能性评估指标体系,运用层次分析法(AHP)与多层次模糊综合决策确定塌方风险事件可能性等级,定性指标由专家评判确定对各可能性等级的隶属度,定量指标的隶属度以正态分布作为隶属函数求出;综合考虑多种事故后果类型,选用当量估计法确定塌方风险事件严重程度;最后基于风险矩阵法确定隧道塌方风险等级。将本模型应用于兴隆隧道1号斜井,经评估该斜井塌方风险等级为Ⅲ级,即较大风险,后续施工中须采取有效措施降低风险,减少风险可能导致的损失。

In order to assess the risk of collapse during the construction of tunnel,taking the determination of its possibility and severity as two principal lines,an index system for the possibility assessment of collapse was established through the literature investigation combined with the risk characteristics,construction status and engineering situation of the tunnel to be assessed,and the probability grade of collapse risk event was determined by using the analytic hierarchy process (AHP) and the multi-level fuzzy comprehensive decision.The memberships of qualitative indexes to each possibility grade were determined through the expert judgment,and the memberships of quantitative indexes were obtained by taking the normal distribution as the membership function.Considering various types of accident consequences comprehensively,the severity of collapse risk event was determined by using the equivalent estimation method.Finally,the risk grade of tunnel collapse was determined by using the risk matrix method.This model was applied to No.1inclined shaft of Xinglong tunnel,and its risk grade of collapse was assessed as grade Ⅲ,namely the larger risk.So the effective measures must be taken to reduce the risk and the loss caused by collapse risk in the subsequent construction.