断裂群碳酸盐岩深埋隧道突水机制及风险减避

Karst Water Inrush Mechanism and Risk Reduction of Carbonate Buried Tunnel in Fault Zone

结合断裂群区内深埋碳酸盐岩隧道突水点的特征,从多条典型断裂群区构造形成环境、地层岩性、岩溶裂隙水边界条件结合隧道施工情况等因素,重点阐述了断裂群区岩溶突水灾害灾变机制。在此基础上建立断裂群区地层岩性、构造形迹、隧道埋深、水文环境、施工工法等6种致灾因子的风险评价模型。利用模糊层次分析法对断裂群隧道涌水风险、岩溶风险及施工安全风险进行评估,得出后二者风险较高。模糊优选出最适宜断裂群隧道岩溶风险物探方案,即TGP+GPR+炮孔加长法对隧址区隐患点进行了重点预测。与开挖揭露情况进行对比验证其准确性,并提出断裂群区岩溶突水的应急措施。最终形成断裂区隧道岩溶风险等级划分标准,以期对后续穿越断裂群隧道岩溶风险安全施工提供咨询。

Based on the characteristic of forming environment, stratum lithology, water bursting disaster in carbonate buried tunnel in fault zone, the boundary condition of fissure karst water and construction condition are analyzed to explain the mechanism of karst water bursting disaster. On these basis, the risk assessment model includes 6 hazard factors （ stratum lithology, structural feature, buried depth, hydrogeological environment and construction method） in fault zone is established. With the result of that, the method of fuzzy analytic hierarchy process is used to estimate the risk of water blushing, karst disaster and construction safety, and the result shows that the last two has high risk in the fault zone tunnel construction. The fuzzy optimum selection is used to choose the most optimum risk detection scheme which is TGP ＋ GPR ＋ hole extension method to predict the hidden risk points of the tunnel site. The excavation exposed situation finally validated the veracity of the risk evaluation, and the emergency measures for controlling water bursting in fault zone are put forward. Finally, the tunnel karst risk grade division standard in fault zone is eventually established to provide consultations for safety construction in follow-up through fracture.