RHINE-RUHR METRO - CASE STUDY NO 1. BOCHUM CITY RAILWAY. CONTRACT 3

The article describes a case study concerning the construction of contract B3 forming part of the underground rapid transit system being commissioned by the city of Bochum as part of the Rhine-Ruhr metro system. Contract B3 is located at the end of the first tunnel section of line B and incorporates a station, a ramp to street level and provision for a future extension of the tunnel section. The construction method used was the new Austrian tunnelling method instead of open cut as originally planned for some sections. Headings were excavated by road-heading machines and a telescopic shovel feeding wheeled loading shovels. Front end loaders transported the spoil to shafts for lifting and removing from site. Steel arches were placed every metre with sprayed concrete for initial support. When the excavation was complete a final in-situ concrete lining was constructed in 8-10 M lengths. Details are given of tunnel dimensions and construction techniques employed.