针对象山隧道全风化花岗斑岩地层，结合前期的上下微台阶预留核心土环状开挖法的变形情况，分析得出该地层施工控制要点，优化施工方案，提出单侧壁导坑开挖法、三台阶+临时仰拱开挖法，坚持执行隧道开挖“十八字”方针，通过加强支护、增加临时支撑、初支快速封闭、二次衬砌紧跟等一系列措施有效地控制了隧道变形。

The exit portal section of Xiangshan tunnel is located in fully weathered granitic porphyry ground, for which "minibench + ring cut" tunneling method is adopted at the primary stage. However, serious deformation occurs during the tunnel construction. On basis of analysis on the deformation, the author summarizes the key points for the tunneling in such ground, optimizes the construction scheme and recommends single side drift tunneling method and "three benches + temporary invert" tunneling method. The guiding principle of "pipe roof reinforcement, strict grouting, short excavation cycle length, strong support, early closing of the reinforcement structure ring and constant measurement" is followed in tunneling. Owing to the strengthened reinforcement, increased temporary support, early closing of the reinforcement structure ring and immediate secondary lining, the deformation of the tunnel is brought under effective control.