Effect of Dimension and Detail on the Capacity of Precast Concrete Parking Structure Diaphragms

摘要

style="text-align: left;">Floor systems in precast concrete parking structures are intended to provide diaphragm action between elements of the lateral load-resisting system during seismic response. Investigations stemming from recent poor seismic performance of some of these structures have raised significant design issues related to the diaphragm. These issues include the possibility of larger-than-expected lateral forces, questionable strength and ductility in joints at critical locations, and the  potential for large drift demand on the gravity system due to excessive diaphragm flexibility. A PCI Daniel P Jenny Research  Fellowship has  examined the behavior of precast concrete parking structure diaphragms. In this paper, the results of nonlinear static analyses of topped and pretopped diaphragms are presented. These    results reveal  the effect of structural dimension and construction details on the diaphragm service level stiffness and ultimate capacity. A companion  paper (a€?Seismic Design Recommendations for Precast Concrete Diaphragms in Long Floor Span Construction,a€? to appear in the next issue of the PCI JOURNAL) will provide seismic design guidelines for long span precast diaphragms. In that paper, the results presented here will be interpreted with respect to expected seismic demands, as  established for flexible diaphragm structures in parallel research.>References style="text-align: left;">1. Rodriguez, M. E., Restrepo, J. I., and Carr, A. J., target="_blank" title="a€?Earthquake Induced Floor Horizontal Accelerations in Buildings,a€?" href="http://dx.doi.org/10.1002/eqe.149 ">a€?Earthquake Induced Floor Horizontal Accelerations in Buildings,a€? Earthquake Engineering and Structural Dynamics, V. 31, No. 3, March 2002, pp.  693-718. style="text-align: left;">2. Wood, S. L., Stanton, J. F., and Hawkins, N. M., a€?Performance of Precast Parking Garages During the 1994 Northridge Earthquake,a€? Proceedings, XIII ASCE Structures Congress, Restructuring:   America and Beyond, V. 1, New York, NY, 1995, pp. 563-566. style="text-align: left;">3. Fleischman, R. B., Sause, R., Rhodes, A. B., and Pessiki, S., a€?Seismic Behavior of Precast Parking Structure Diaphragms,a€? Proceedings, XIV ASCE Structures Congress: Building an International  Community of Structural Engineers, Edited by S. K. Ghosh, V. 2, Chicago, IL, April 15-18, 1996, pp. 1139-1146. style="text-align: left;">4. Fleischman, R. B., Sause, R., Pessiki, S., and Rhodes, A. B., target="_blank" title="a€?Seismic Behavior of Precast Parking Structure Diaphragms,a€?" href="http://dx.doi.org/10.15554/pcij.01011998.38.53 ">a€?Seismic Behavior of Precast Parking Structure Diaphragms,a€? PCI JOURNAL, V. 43, No. 1, January-February 1998, pp. 38-53. style="text-align: left;">5. Fleischman, R. B., Farrow, K. T., and Eastman, K., target="_blank" title="a€?Seismic Response of Perimeter Lateral-System Structures with Highly Flexible Diaphragms,a€?" href="http://dx.doi.org/10.1193/1.1490547 ">a€?Seismic Response of Perimeter Lateral-System Structures with Highly Flexible Diaphragms,a€? Earthquake Spectra, V. 18, No. 2, May 2002, pp. 251-286. style="text-align: left;">6. Fleischman, R. B., and Farrow, K. T., target="_blank" title="a€?Seismic Design Recommendations for Precast Concrete Diaphragms in Long Floor Span Construction,a€?" href="http://dx.doi.org/10.15554/pcij.11012003.46.62 ">a€?Seismic Design Recommendations for Precast Concrete Diaphragms in Long Floor Span Construction,a€? scheduled for publication, PCI JOURNAL, V. 48, No.  6, November-December 2003. style="text-align: left;">7. Bashaw, D., Nakaki, S., and Bondy, D., Transmittal from Englekirk and Nakaki Inc., January 1995. style="text-align: left;">8. ICBO, Uniform Building Code, International Conference of Building Officials, Whittier, CA, 1994.