Title:
Seismic Retrofitting of Bridge Foundations
Author(s):
David I. McLean and M. Lee Marsh
Publication:
Structural Journal
Volume:
96
Issue:
2
Appears on pages(s):
174-182
Keywords:
bridges (structures) columns (supports); ductility; earthquake resistant structures; foundations; shear strength
DOI:
10.14359/608
Date:
3/1/1999
Abstract:
This paper describes an experimental study investigating retrofitting measures for improving the seismic performance of the foundations of existing bridges. Retrofit measures for both pile-supported and spread footings were investigated. Tests were conducted on 1/3-scale footing and column assemblages that incorporated details selected to represent deficiencies common in older bridges. Tests on the as-built specimens resulted in a brittle failure due to insufficient joint shear strength in the column- footing connection. An added reinforced concrete overlay provided an effective retrofit for the as-built footings. In specimens that were overturning critical, increased overturning resistance was achieved by enlarging the footing plan size, by providing additional piles, or by providing tie-downs through the footing.