Large-scale improvement of converting a Japan’s first subway station constructed by the shield tunneling method into that of an open-cut method: Kiba Station on the Tozai Line

Tokyo Metro has constructed subway lines since the 1950s to develop a subway network in the central part of the Tokyo Metropolitan Area. At present, it operates a 200-km network of nine subway lines, which was, for the most part, completed when the entire Fukutoshin Line was opened for service in 2008. Tokyo Metro is now working to enhance safety and raise customer satisfaction by upgrading the quality of service. This paper reports on the contents and the construction methods used to achieve a seamless flow of passengers at Kiba Station on the Tozai Line. This is an example of the improvements being made in the existing subway network to help establish an affluent society in the future.