For TOKYO WAN AQUA-LINE (Traps -Tokyo Bay Highway) the slurry shield method was employed. Because of the long length of tunnel the shield machines from both side were joined under the ground. In this process, the ground freezing method was used as an assistant method and slurry around shield machine was frozen at -30°C. Though machines were also cooled, it was difficult to employ pre- and/or post-heat for prevention from cold cracking. In this study, the welding procedure for water proof and reinforcement welding without pre- and/or post-heat to obtain enough joint strength was examined by experiments. The propriety of welding design was also confirmed in mock-up test. The actual underground connection was finished and TOKYO WAN AQUA-LINE is now under service.
