基于破碎带涌水预测的山岭隧道施工许可机制研究

 突涌水事故是山岭隧道穿越各种破碎带时遭遇的主要地质灾害，建立隧道施工许可机制是减少损失和控制风险的有效途径。隧道施工许可机制是一个基于涌水量预测、地质预报、封堵加固措施、开挖方法、施工组织管理和综合评价的风险控制机制，是一个动态调控机制，只有当许可评价的风险在可接受的范畴内才可以施工，否则应调整施工措施，避免灾害的发生。首先，基于经典地下水理论建立涌水量计算模型，实现对隧道穿越破碎带可能涌水量的超前预测；针对待开挖的隧道，基于综合超前地质预报技术体系，实现对掌子面前方待开挖破碎带的规模、空间展布和岩体特征的精确预报；然后，将地质预报和涌水量预测结果同拟采用的封堵加固措施、开挖方法、施工组织管理等因素共同构成施工许可的评价指标，通过综合评价方法判定施工的风险，确定施工的安全性；最后，将此方法应用于泰宁隧道穿越F2破碎带的施工中，根据评价结果，确保隧道安全通过此破碎带。基于破碎带涌水预测的施工许可机制在隧道突水预测与灾害控制方面具有明显作用，其分析结果相对准确可靠，具有广泛的应用前景。

Construction license mechanism of mountain tunnels based on inrush prediction of fracture zones

Water inrush is a typical geologic hazard when the mountain tunnels pass through different fracture zones，and establishing the license mechanism of tunnel construction is an effective way to reduce the damage and to control risk. The license mechanism of tunnel construction is a risk control measure based on the water inflow forecast，geological prediction，plugging reinforcement measures，excavation method，construction management and comprehensive evaluation. Only when the risk of construction is within the acceptable category or the construction measures are adjusted to avoid the occurrence of disaster，the constructions will be permitted. A water inflow model was established to predict the possible water inflow when tunneling passed through the fracture zone. The scale，spatial distribution and rock characteristics of the fracture zone to be excavated in front of tunnel face were inspected accurately with the comprehensive advanced geological prediction system. The results of the geological inspection and water inflow prediction were combined with the proposed plugging reinforcement measures，excavation method，construction management and other factors together to form the evaluation index of construction license. The risk and safety of construction can be determined through the comprehensive evaluation method. This method was applied successfully to the Taining tunnel through the F2 fracture zone in construction and ensured the safety of the tunnel through the fracture zone.