Keihin Kansen Mainline: A Typical Urban Pipeline in Japan

The KEIHIN KANSEN pipeline of Tokyo Gas Co. Ltd., the construction of which was decided in 1986, has finally been completed after a long design and construction period of 13 years. KEIHIN KANSEN is a typical urban pipeline connecting Tokyo and Yokohama, the most crowded cities in Japan. This paper outlines the plan and concept of safety, and quality of the pipeline. Here are in particular described the piping works within the Keihin/ Asahi tunnel by shield method, focusing on its design scheme, study results, and experiments on pipeline supports for large reaction force.