Two methods of concrete lining machine bored tunnels : Nelsen, A A Paper to 3rd Australian Tunnelling Conference, Sydney, 12–15 Sept 1978, 6P

Abstract

The Melbourne and Metropolitan Board of Works has constructed over 30 kilometres of various sized machine bored rock tunnels in the last 10 years. All of these tunnels for sewerage have been temporarily supported during excavation and completed by placing an insitu concrete lining. Two methods of constructing the concrete lining have evolved. For smaller sewers, 1.8 metres diameter when lined, the full circle bulkheaded pour method is used and for larger tunnels from 2.59 metres to 3.51 metres diameter when lined, the full circle continuous pouring method is used. The paper explains both methods and gives important details such as, concrete mixes, formwork, plant and equipment for transporting and placing the concrete, crew requirements and production achieved.