bench cut method

method),台阶法 (bench cut method)和 导坑法(drift method)等。

... 5.全断面开挖法（ full face excavation method) 6.正台阶法（ bench cut method) 7.环形开挖预留核心土法（ ring cut method) ...

下导坑超前台阶法,bottom drift with... ... ) top heading and bench method 顶导坑及平台法 ) bench cut method 上下台阶法 ...