大型隧道涌水常发生于岩溶发育地区，在传统认为缺水、贫水的红层地区实属罕见。飞仙关隧道作为雅康高速公路关键性控制工程之一，在施工至K23+708标段时发生特大涌突水，涌水量高达1.74×106 mL/s，经过一个周期性涌水，稳定流量约为3.48×105 mL/s。以飞仙关隧道为例，结合前人对隧道涌水的水化学分析成果，采用自主研发的专门用于模拟隧道涌水过程的渗流试验槽装置，将飞仙关隧道K23+658～883段（225 m）原型按一定比例缩小为模型，选取飞仙关向斜两个典型剖面进行物理模拟试验。通过对试验涌水量的拟合分析，对比隧道实测涌水特征，验证了顺层顺轴向、顺层绕轴向两种涌水模式，确定了涌水来源与通道。试验结果表明该模型稳定可靠，研究方法及结果对今后类似工程的研究具有指导和借鉴意义。

Water inrush from large tunnels often occurs in Karst areas,which are rare in red layers where water is traditionally considered to be poor.As one of the key control projects of Yakang Expressway,Feixianguan Tunnel has a huge water inrush when it reaches the K23+708 tender section. The water inrush volume is up to 1.74×106 mL/s. After a periodic water inrush,the steady flow is about 3.48×105 mL/s.Taking the Feixianguan tunnel as an example,this paper combines the previous results of hydrochemical analysis of water gushing in the tunnel,using the self developed percolation test slot device,which was specially used to simulate the process of tunnel water gushing,the prototype of K23+658~883 segment (225 m) of Feixianguan tunnel to a certain proportion as a model,and two typical sections of Feixianguan syncline were selected for physical simulation test.Through the fitting analysis of the test water inflow and the comparison of the characteristics of the measured water gushing in the tunnel,two kinds of water inrush modes of along the axis and around the axis were verified,and the source and channel of the water gushing were determined.The experimental results showed that the model was stable and reliable,and the research method and results may use as guidance and reference for the future research of similar projects.

国家自然科学基金（41472275）；四川交通科技项目（2013 C10-2）