Safety systems for the Trans-Tokyo Bay Highway Tunnel project.pdf

FIRE AND LIFE SAFETY Safety Systems for the Trans-Tokyo Bay Highway Tunnel Project N. Yamada and Y. Ota Abstract - - This paper describes the safety facilities developed for the Trans-Tokyo Bay Highway Tunnel, at present the longest underwater road tunnel in the world. In particular, the paper describes the safety equipment, evacuation facilities and plans, public relations system for safety. ? 1999 P u b l i s h e d by E l s e v i e r Sc i ence Ltd . ALl r i g h t s r e se rved . 1. Introduction T he area around Tokyo Bay houses Japans major industries, and at the same time is the dwelling area of about 30 million people one- quarter of Japans population. For many years, both the areas industries and its residents have wished for a connection across the Tokyo Bay. But such a project presented diffi- cult conditions. First, it is predicted that a major earthquake will occur in the Tokyo area in the near future. In addition, the area where the tunnel is located consists of very soft soil that has the consistency of sof~ cheese. In spite of these and other conditions, a road with a total ler~gth of 15 km was realized after decades of planning and construction. The Trans Tokyo Bay (T.T.B.) Highway project comprises a 9.5-kin- long tunnel to the west and a 5.5-kin-long bridge to the east. An aver- age traffic volume of around 11,000 ve- hicles per day was obs,~rved at the end of October 1998, nearly a year after the highway was opened to service. This paper describes general plan- ning for the tunnel, ibcusing on provi- sion of safety features and facilities, as well as the public relations system for making drivers aware of these features. Figure 1. Location map of the Trans-Tokyo Bay Highway. 2. General Planning In 1961, design work began for the T.T.B., planned as a connection between the Kawasaki District on the West Side and the Chiba District on the East Side of the Tokyo Present address: Norio Y.~mada, Japan High