IS 4756-1978

标准号：IS 4756-1978
发布日期：1978/9/1 12:00:00
实施日期：1999/12/31 12:00:00
适用范围：1.1 This standard lays down the safety requirements for tunneling and underground excavations in rocks and soft strata.1.2 This code does not cover tunnels made in connection with mining operations, gassy tunnels, and also tunnels made in running ground (see 2.3 ), where special methods like shield tunneling are adopted.Note— 'Gassy tunnel ' wherever used in this code shall mean a tunnel in any part of which flammable gas is present or is likely to occur including a tunnel which is adjacent to or is approaching any such place.1.3 Safety precautions to be observed during blasting and related drilling operations are covered separately in IS : 4081-1967〓.