宜万铁路高阳寨隧道长4730m，其中出口端为双线大跨加燕尾段，穿越坡积体、堆积体、岩溶和富水的断裂破碎带等地质复杂地段，通过对该隧道大跨加燕尾段的施工方案制定和实施，介绍在复杂地质地段的大跨隧道的施工技术及施工注意事项。

Gaoyangzhai tunnel on Yichang～Wanzhou railway is 4730m long. The exit portal section of Gaoyangzhai tunnel, which consists of largespanned doubletrack tunnel section and swallowtailshaped tunnel section, goes through such complex geological conditions as talus, cumulated ground and fracture zones containing karst and rich water. On basis of presenting the determination and execution of the construction plan for the largespanned section and the swallowtailshaped section of Gaoyangzhai tunnel, the author describes the construction technology for largespanned tunnels in complex geological conditions and presents the issues to which attention should be paid during tunnel construction.