1/7/2019 · The suitable excavation method for running tunnels construction of 4–6 m deep excavation is cut-and-cover (or open-cut) construction (Read, 2004a). This method consists of tunnel construction by deep excavation in trench, construction of the permanent tunnel structure, and subsequent backfill and reinstatement of the ground surface ( Muir Wood, 2000 , Puller, 1996 , Yun, 2019 ).