Title:
BENT BOLT INSERTION HOLE PROTECTION PIPE
Document Type and Number:
Japanese Patent JP2769425
Kind Code:
B2
Abstract:
PURPOSE: To avoid stress concentration when a bent bolt is tightened thereby preventing cracks from being generated by embedding a bent bolt protection pipe, wherein a plurality of studs are formed, by casting, integrally with the outer surface thereof, in a joint of concrete segments.
CONSTITUTION: A plurality of studs 6A, 6B... are formed integrally with the outer surface of an arcuately curved cylindrical pipe 5 by casting to form a protection pipe 5. And the length of the studs can be varied and the studs may be provided not only on the top side of the pipe 5 but may be provided so as to be radially inclined with respect to the section of an insertion bore 7. Next, the pipe 5 is embedded in a connection part of a concrete segment 1 to engage it with an adjacent segment thereby forming an arcuate shape, and the end of the pipe 5 is inserted into a joint hole 2. And when a bent bolt 4A is inserted into the pipe 5 and a nut 4B is screwed onto the bolt, stresses are widely dispersed in the concrete of the connection part. By this method, cracks are prevented from being generated.
Inventors:
Kazumasa Konishi
Hideo Yamamoto
Hideo Yamamoto
Application Number:
JP29772693A
Publication Date:
June 25, 1998
Filing Date:
November 29, 1993
Export Citation:
Assignee:
Geostar Corporation
International Classes:
E21D11/08; E21D11/04; (IPC1-7): E21D11/04; E21D11/08
Attorney, Agent or Firm:
Toshi Hisamon