Development of Expressway network

Promoting the development of Expressway networks while deploying various technologies to create day and night

Construction of tunnels in urban areas

Shield machines are used for tunnel construction in urban areas such as the outer ring road and Ken-O Road Expressway. In particular, the outer ring road (between the Kan-Etsu Expressway and the Tomei Expressway) uses a machine with a diameter of about 16 m as the largest cross section in Japan.

Photograph of construction situation by shield method
Construction status by shield method
Photo of Japan's largest cross-section shield machine
Japan's largest cross-section shield machine

Girder construction of various bridges

When constructing a bridge, the crossing roads are closed at night and the girders are erected all at once by a multi-axle trolley. Since it is difficult to install a crane in mountainous areas or on rivers, the cable erection (direct suspension) construction method is used. The erection construction method according to local conditions is adopted.

Image photograph of collective installation with multi-axle trolley
Collective erection by multi-axle truck
Photograph of the construction situation by the cable erection method
Construction status by cable erection method

Special earthwork site

At the site of the Tohoku Chuo Expressway, we pass through the wetland of Lake Hakuryu, so we took measures to soften the soil by the vacuum consolidation method in order to increase the strength of the soil. In addition, during the construction of Domanzan, which is a long-cherished earth slope, countermeasures were taken using rock bolts and concrete glue frames to prevent collapse.

Photograph of construction situation of vacuum consolidation method
Construction status of vacuum consolidation method
Photograph of construction situation of long important soil slope (12 steps)
Construction status of long-cherished earth slope (12 steps)