Seismic Performance of Precast Segmental Bridge Superstructures with Internally Bonded Prestressing Tendons

摘要

style="text-align: left;">A research project is currently in progress to investigate the seismic performance of segment-to segment joints of precast segmental concrete bridges. This paper presents the experimental and analytical  results of two large-scale tests which model the superstructure response of a prototype precast segmental bridge, post-tensioned with internally bonded tendons, under fully reversed vertical cyclic  displacements. The joints of the first test unit were epoxy bonded with no reinforcement crossing the joints other than the prestressing steel. The second test unit had a reinforced cast-in-place deck closure with the remaining portions of the joints connected by epoxy. Both test units were  subjected to fully reversed cyclic loads simulating earthquake vertical motions. It was found that both test units could undergo significant seismic displacements, but their failure modes were  considerably different. The paper also presents results from nonlinear finite element modeling of  the simulated seismic response of the test units. The results showed that segment-to-segment joints could undergo significant repeated opening and closure before failure. >References style="text-align: left;">1. AASHTO, Guide Speccation for Design and Construction of Segmental Concrete Bridges, Second Edition, American Association of State Highway and Transportation Officials, Washington, DC,  1999. style="text-align: left;">2. AASHTO-PCI-ASBI, Segmental Box Girder Standards for Span-by-Span and Balanced Cantilever Construction, American Association of State Highway and Transportation Officials, Washington,  DC, Precast/Prestressed Concrete Institute,  Chicago, IL, and American Segmental Bridge Institute, Phoenix, AZ, 1997. style="text-align: left;">3. AASHTO, Standard Speci.fications for Highway Bridges, 13th Edition, American Association of State Highway and Transportation Officials, Washington, DC, 1983. style="text-align: left;">4. Dowell, R. K., Silva, P. F., and Seible, F., a€?Precast Segmental Bridge Performance in Seismic Zones: Phase I, Test Unit Design,a€? Progress Report submitted to Caltrans, April 2000, 30 pp. style="text-align: left;">5. ASBI,  Recommended Contract Administration Guidelines for Design and Construction of Segmental Concrete Bridges, American Segmental Bridge Institute, Phoenix, AZ, March 1995, pp. 109-116. style="text-align: left;">6. Chopra, A. K., Dynamics of Structures, Prentice Hall, Inc., Princeton, NJ, 1995, 729 pp. style="text-align: left;">7. Collins, M. P., and Mitchell, D., Prestressed Concrete Structures, Response Publication, Toronto, Canada, 1997. style="text-align: left;">8. Hibbitt, Karlson, and Sorenson, ABAQUS Usera€?s and Theory Manual, Version 5.8, 1999. style="text-align: left;">9. ANATECH Corporation, ANACAP-U Usera€?s and Theory Manual, Version 2.5, 1997.