The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 18, 1997
Filed:
May. 09, 1994
Mitsutoshi Hayashi, Omiya, JP;
Mitsuo Ishitani, Sapporr, JP;
Tokyo Gas Co., Ltd., Tokyo, JP;
Nippon High Strength Concrete Co. Ltd., Hokkaido, JP;
Abstract
A tunnel liner used for a shield tunneling method for a tunnel having a diameter of 1.5 to 7 m is fabricated by dividing a ring-shaped liner into a plurality of parts in the circumferential direction. The tunnel liner is required to be excellent in the dimensional accuracy with respect to the outer peripheral surface, to be tight, to be high in strength, and to be high in water tightness at the abutment between the adjacent liners. The tunnel liner is fabricated by a method of filling each arcuate enclosed hollow form with concrete, vibro-compacting concrete, molding the end surfaces of the tunnel liner, mounting the forms within a centrifugal molding drum, and tightly molding the outer peripheral surface of the forms by applying of a centrifugal force. According to this fabrication method, it is possible to effectively fabricate an excellent tunnel liner at a low cost.