2003 Volume 13 Pages 195-200
The mountain tunneling method has recently been adopted in an increasing number of cases in urban areas. There have, however, been few cases where complete watertightness was achieved, which resulted in massive repair and increased life-cycle cost. Our company developed new waterproofing technology that provides a “ watertight structure that does not prevent concrete filling and is in close contact with the shotcrete”. The technology enables the construction of a highly watertight structure that is applicable to urban mountain tunnels. Applying the technology is expected to greatly improve the quality of waterproofing systems and linings not only in urban watertight tunnels but also in ordinary mountain tunnels. This paper describes the application of the technology at the Minaminagareyama Tunnel.