Site: East Kanto Expressway
Kasumi, Chiba, Japan
Date Visited: October 1996
Contact: M. Uemura, Tonen Corporation
Makato Saito, Deputy Manager, Tonen Corporation
Summary: Seismic retrofit of rectangular columns.


Carbon fiber tow sheet (2,800 m2 total) was used to seismically rehabilitate rectangular columns using two layers of sheet, one in the vertical direction and the other in the horizontal (or circumferential) direction. It was unclear as to which grade of sheet was used but it was reported that the application cost was $15/m2. It was also reported that in the original construction designs, the longitudinal steel had been curtailed. The vertical carbon fiber sheet was used partially to overcome this deficiency. The project was completed in June 1996. Figure B.86 shows the columns after retrofit and Figure B.87 shows a close-up of the placement of vertical fabric on a column. No special rounding of corners was noticed.

Fig. B.86. Overall view of retrofitted columns.

Fig. B.87. Close-up showing placement of vertical sheets.

Published: October 1998; WTEC Hyper-Librarian