以成兰铁路平安隧道软岩段施工为背景，采用数值模拟、理论计算和现场试验等方法对全断面（含仰拱）法和台阶法施工时的围岩变形、初期支护受力及施工组织等方面进行比较分析，结果表明： 上下台阶法相比全断面（含仰拱）法开挖围岩要稳定，但全断面（含仰拱）法开挖累计变形量更小； 2种方法开挖产生的剪切、拉伸破坏区的范围大小相近，均能满足结构安全的需要，而全断面（含仰拱）法的施工质量比上下台阶法易于控制； 全断面（含仰拱）法在人员投入和施工进度等方面明显优于上下台阶法。

Comparison between bench method and fullface method (including invert arch) for soft rock section of Ping’an Tunnel on ChengduLanzhou Railway is made in terms of surrounding rock deformation, primary support stress and construction organization by using numerical simulation, theoretical calculation and site test. The study results show that: 1) The stability of surrounding rock of tunnel constructed by bench method is superior to that constructed by fullface method; and the accumulated deformation of tunnel constructed by fullface method is smaller than that constructed by bench method. 2) The sizes of shear zone and tensile failure zone of tunnel constructed by 2 methods are almost the same. The construction quality of tunnel constructed by fullface method is easier to control. 3) The fullface method is superior to bench method in terms of labor and construction schedule.