ABSTRACT
The forming and casting of concrete walls inside the tunnels is the last and probably one of the most critical stages of the tunnel construction in addition to the other stages of construction such as geotechnical survey, excavation, stabilization with steel-mesh placement and shot grid concrete, and post-tensioned soil anchorages. The stability of a tunnel most commonly relies on the shape and quality of walls, with the exception of Austrian method which uses concrete wall just for decoration.
