. . . . . . . . . . . . . . . . . . "Deep level underground is construction that is 20 metres or more below ground and not using the cut-and-cover method, especially train stations, air raid shelters and bunkers, and some tunnels and mines. Cut-and-cover is a simple method of construction for shallow tunnels where a trench is excavated and roofed over with an overhead support structure that is strong enough to carry the load of what is to be built above the tunnel."@en . . . . . . . . . . . . . . "1119024329"^^ . . . . . . . . . . "8758"^^ . . . . . . . . . . . . . . . . . "49619199"^^ . . "Deep level underground"@en . . . . . . . . . . . . . . . . . . . . . . . . "Deep level underground is construction that is 20 metres or more below ground and not using the cut-and-cover method, especially train stations, air raid shelters and bunkers, and some tunnels and mines. Cut-and-cover is a simple method of construction for shallow tunnels where a trench is excavated and roofed over with an overhead support structure that is strong enough to carry the load of what is to be built above the tunnel."@en .