FLEXURAL RETROFIT OF CIRCULAR REINFORCED CONCRETE BRIDGE COLUMNS BY STEEL JACKETING. COLRET - A COMPUTER PROGRAM FOR STRENGTH AND DUCTILITY CALCULATION. PRELIMINARY REPORT
This report presents the development of an analytical model, based on moment-curvature analysis at the critical section, for the prediction of flexural strength and ductility in prismatic circular bridge columns. Columns are treated as vertical cantilevers subjected to axial compression and lateral inertial force. Passive confinement of the concrete core by the transverse steel is accounted for using a realistic model for confined concrete. Post-yield deformation of the column is predicted on the basis of an elasto-plastic idealization with plasticity concentrated in a localized hinged region. Failure modes such as that precipitated by shear or bond-slip at the lap-splices of the longitudinal bars are not considered in the model. The analytical model is extended to columns with fully grouted steel jackets which are assumed to contribute to the ductility of the column by providing confinement to the column concrete without significant enhancement of the flexural strength. The increase in lateral stiffness of the column due to the steel jacketing is taken into account by considering the effective bond transfer between the jacket and column for composite action. Deformation beyond yield of the column occurs in a reduced plastic hinge length. The increase of shear strength in the encased region of the column is also considered. The model is coded in a computer program to provide bridge engineers a simple and reliable means of assessing the performance of existing bridge piers so that deficient piers can be identified, and to allow an assessment of the improved column performance after retrofit. The reliability of the model is verified through experimental testing of large scale column units.
- Prepared in cooperation with the State of California, Business and Transportation Agency, the U.S. Department of Transportation, Federal Highway Administration, and the National Science Foundation.
University of California, San DiegoDepartment of Applied Mechanics and Engineering Sciences
La Jolla, CA United States 92093-0085
Sacramento, CA United States 94272-0001
Washington, DC United States 20590
- Chai, Y H
- Priestley, MJN
- Seible, F
- Publication Date: 1991-10
- Pagination: 132 p.
- TRT Terms: Bridge piers; Columns; Computer programs; Ductility; Earthquake engineering; Earthquake resistant design; Flexural strength; Forecasting; Jacketing (Strengthening); Reinforced concrete; Reinforcement (Engineering); Retrofitting; Steel
- Subject Areas: Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls;
- Accession Number: 00720039
- Record Type: Publication
- Source Agency: Federal Highway Administration
- Report/Paper Numbers: UCSD/SSRP-91/05, F88SD06
- Contract Numbers: RTA-59G267
- Files: TRIS, USDOT, STATEDOT
- Created Date: Apr 2 1996 12:00AM