Rock Support
As the tunnel is incrementally excavated the roof and sides of the tunnel need to be supported to stop the rock falling into the excavation. The philosophy and methods for rock support vary widely but typical rock support systems can include:
- Rock bolts or rock dowels
- Shotcrete
- Ribs or mining arches and lagging
- Cable bolts
- In-situ concrete
Typically a rock support system would include a number of these support methods, each intended to undertake a specific role in the rock support such as the combination of rock bolting and shotcrete.
Read more about this topic: Drilling And Blasting
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—Rutherford Birchard Hayes (1822–1893)