基于风险动态评估与控制的岩溶隧道施工许可机制

Construction permit mechanism of karst tunnels based on dynamic assessment and management of risk

翻坝高速鸡公岭隧道穿过寒武系石龙洞组强岩溶含水层,地下水位高于隧道底板约150~200 m,施工中极易发生大型突水突泥灾害。为控制施工风险,研究了隧址区岩溶发育特征,突水突泥风险孕险环境、致险因子、动态管理与控制方法,建立了基于综合赋权专家评分法的初步评估、二次评估与动态评估模型,首次提出并成功实施了一种基于隧道施工风险动态评估的风险控制新机制：施工许可机制。该机制不仅可在岩溶隧道施工风险控制过程中应用,对于其他类型隧道与工程施工风险控制亦有借鉴意义,已成功应用于翻坝高速鸡公岭隧道突水突泥施工风险控制,并开始应用于宜巴高速隧道施工中,岩溶、软岩大变形、塌方等灾害风险控制。

Jigongling Tunnel of Fanba Expressway passes through strong karst aquifer of Cambrian Shilongdong Fm,and water table is about 150~200 m above the tunnel floor.Large-scale water inrush and mud irruption are easy to happen.In order to control construction hazards,the karst development characteristics of the tunnel site are studied.The risk surroundings,factors and dynamic management for water inrush and mud irruption of the karst tunnel are analyzed.Preliminary,secondary and dynamic risk assessment models based on the comprehensive weights and the expert scoring method are established.A new management mechanism of construction risk,which is a kind of construction permit mechanism based on risk assessment of water or mud inrush,is developed and successfully carried out for the first time.This mechanism not only can be used for the risk management of karst tunnels,but also for other kinds of engineering constructions.It is successfully applied in the karst risk management of Jigongling Tunnel on the line of Fanba Expressway,and it is being employed to manage the construction risk of karst,and the large deformation of soft rock and collapse in Yichang-Badong Expressway.