1, safety matters are different: the main risk factors in the process of tunnel excavation are arch frame toppling injury, squeezing injury, soil collapse injury, falling object injury, electric shock injury, etc. , erection work should mainly check the working state of the support regularly and irregularly.

2. Different operation methods: According to the control points and disclosure given by surveyors, the positions of vault and arch foot should be well controlled during tunnel excavation, and the cooperation with on-site technicians should be well done. The erection work must be carried out under the unified command of the site foreman. When hoisting the steel arch, the slogan is unified and the action is coordinated.