STATE OF CALIFORNIA DEPARTMENT OF TRANSPORTATION TECHNICAL REPORT DOCUMENTATION PAGE TR0003 (REV. 10/98) 1. REPORT NUMBER CA12-2001 2. GOVERNMENT ASSOCIATION NUMBER 3. RECIPIENT’S CATALOG NUMBER 4. TITLE AND SUBTITLE Seismic Performance of an I-Girder to Inverted-T Bent Cap 5. REPORT DATE September 2011 Connection 6. PERFORMING ORGANIZATION CODE 7. AUTHOR(S) Rick Snyder, Justin Vander Werff, Zach Thiemann, Sri Sritharan & Jay Holombo 8. PERFORMING ORGANIZATION REPORT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS Department of Civil, Construction & Environmental Engineering Iowa State University Ames, Iowa 50011 10. WORK UNIT NUMBER 11. CONTRACT OR GRANT NUMBER 59A0615 12. SPONSORING AGENCY AND ADDRESS California Department of Transportation Division of Engineering Services, MS-09 1801 30 th Street Sacramento CA 95816 13. TYPE OF REPORT AND PERIOD COVERED Final 14. SPONSORING AGENCY CODE 15. SUPPLEMENTAL NOTES 16. ABSTRACT This report presents the research conducted as part of an investigation for the California Department of Transportation (Caltrans) regarding the seismic response and overall moment capacity of precast I-girder to inverted-T bent cap bridge connections for seismic applications. The current design practice, as outlined by Caltrans’ Seismic Design Criteria, assumes that the connection between the precast I-girders and the inverted-T bent cap will degrade in a seismic event and shall therefore be designed as a pinned connection, making the precast girder option for seismic bridges inefficient. A prototype I-girder to inverted-T bent cap bridge and a 50% scale test unit was designed in order to investigate the behavior of the as-built girder-to-cap connection region. Additionally, per the request of Caltrans, an improved girder-to-cap connection detail was developed in order to ensure a fully continuous moment connection between the I-girders and inverted-T bent cap. A finite element grillage model was developed using ABAQUS and SAP2000 and was used to predict the global and local responses of various aspects of the test unit. The test unit was constructed and tested in two phases of quasi-static cyclic testing. The first phase was a horizontal load test phase, which simulated the effects of gravity and seismic loads on the entire test unit. The second phase was a vertical load test phase, which specifically focused on the positive and negative moment capacity of the connections. Both the results of the finite element grillage model and the testing were used to make conclusions regarding the performance of an I-girder to inverted-T bent cap bridges. It was concluded that the current I-girder to inverted-T bent cap bridge connection is capable of acting as a fully continuous connection for both positive and negative moments during both gravity and seismic loading, contrary to the design assumptions stated in Caltrans’ Seismic Design Criteria. The improved connection detail demonstrated the ability to ensure a fully continuous moment connection between the I-girders and inverted-T bent cap. Both connection details also exhibited a significant moment resistance beyond what was expected during the vertical load test although the as-built connection eventually failed under positive moments at moderate to large displacements. 17. KEY WORDS Pre cast I-girder, inverted-tee bent cap, seismic design 18. DISTRIBUTION STATEMENT No restrictions. This document is available to the public through the National Technical Information Service, Springfield, VA 22161 19. SECURITY CLASSIFICATION (of this report) Unclassified 20. NUMBER OF PAGES 306 21. PRICE Reproduction of completed page authorized
Seismic Performance of an I-Girder to Inverted-T Bent Cap Connection
Jun 18, 2023
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Related Documents
