Mitsui Kensetsu Kabushiki Kaisha

Shigeo Takamiya

Kazutoshi Inoue

Toshio Furuta

Kenzo Tsutaya

A method and apparatus for constructing an enlarged tunnel in a portion of a predetermined region of an existing tunnel. A circumferentially enlarged portion is excavated to define a starting base for a shield machine. The shield machine is positioned in the circumferentially enlarged portion and advanced forward along the existing tunnel in order to enlarge the circumference in the predetermined region of the existing tunnel. A section of a tubular liner lining the existing tunnel is broken and removed therefrom. Thereafter, the resultant enlarged tunnel portion is lined with segments.

Method for constructing an enlarged tunnel and apparatus for forming the

A shield machine for enlarging a portion of an existing tunnel includes an inner and outer double cylinder shaped shield machine body with a cylindrical outer shield portion and a cylindrical inner guide portion designed to be driven in an axial direction of an existing tunnel and along an outer circumferential surface of primary assembly segments lining the existing tunnel. Jack members are provided for pushing forward the shield machine body by receiving a reaction from a reaction member such as secondary assembly segments lining a constructed enlarged tunnel. A scraper member is positioned adjacent to the inner guide portion for removing a back-filling agent on the outer surface of the primary assembly segments.

Growing community of inventors

Tokyo, Japan

Shigeo Takamiya