NEHRP Clearinghouse
- Title
- Seismic Response of Column/Cap Beam Tee Connections with Cap Beam Prestressing.
- File
- PB97185912.pdf
- Author(s)
- Sritharan, S.; Priestley, M. J. N.; Seible, F.
- Source
- Business, Transportation and Housing Agency, Sacramento, CA. California Dept. of Transportation., December 1996, 332 p.
- Identifying Number(s)
- UCSD/SSRP-96/09
- Abstract
- Concrete bridge joints in California were detailed with no shear reinforcement in the 1950s. The probable consequence of such poor detailing was demonstrated on an as-built tee (interior) joint from the Santa Monica Viaduct in Los Angeles. When a redesign of this joint was considered with the conventional design methods based upon the maximum joint shear forces, it resulted in a considerable amount of joint reinforcement, causing congestion of steel within the joint. This has been identified as a major construction problem in concrete bridge construction. Three redesigns of the prototye joint were sought with the objective of reducing the amount of reinforcing steel within the joint, thereby ensuring constructability. In all three designs, force transfer models were employed in determining the appropriate amount of joint reinforcement rather than using the joint shear forces as the design parameter. When the cap beam was designed with full prestressing, it was also shown that precast construction can be adopted as an alternative to cast-in-place construction for building multi-column concrete bents. The details of the joint design, seismic performance of all three redesigned units and some design recommendations are presented in this report.
- Keywords
- Bridges (Structures); Seismic design; Prestressed concrete; Reinforced concrete; Precast concrete; Caps (Supports); Earthquake engineering; Joints (Junctions); Los Angeles (California)