{"version":"1.0","type":"link","title":"Deep level underground - Newikis","description":"Deep level underground is construction that is 20 m (66 ft) 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…","provider_name":"Newikis","provider_url":"https://newikis.com","cache_age":86400}