Stiffness Reduction Factor for Flat Slab Structures under Lateral Loads
Publication: Journal of Structural Engineering
Volume 135, Issue 6
Abstract
Effective beam width model (EBWM) has been widely used for predicting lateral drifts and slab moments in flat slab structures under lateral loads. As the slab moment due to lateral loads increases, slab stiffness decreases due to crack formation. The accuracy of the EBWM strongly depends on how the reduced slab stiffness is estimated. For this purpose, this study developed equations for calculating slab stiffness reduction factor by conducting nonlinear regression analysis using stiffness reduction factors estimated from collected test results. The slab stiffness reduction factor is defined as a ratio of reduced slab stiffness due to crack formation to the stiffness of the uncracked slab section. For verifying the proposed equation, the lateral stiffness of two slab–column connection specimens tested by the writers was compared with the lateral stiffness calculated using the EBWM with the proposed stiffness reduction factor. Further, two flat plate specimens having two continuous spans were also considered for verifying the proposed equations for .
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Acknowledgments
The writers acknowledge the financial support provided by the Korea Research Foundation (D01140) and SRC/ERC (R11-2005-056-04002-0). The views expressed are those of the writers, and do not necessarily represent those of the sponsors.
References
American Concrete Institute (ACI). (2005). Building code requirements for structural concrete and commentary, ACI Committee 318, Detroit.
Banchik, C. A. (1987). “Effective beam width coefficients for equivalent frame analysis of flat-plate structures.” ME thesis, Univ. of California, Berkeley, Calif.
Farhey, D. N., Adin, M. A., and Yankelevsky, D. Z. (1993). “RC flat slab-column subassemblages under lateral loading.” J. Struct. Eng., 119(6), 1903–1916.
Grossman, J. S. (1997). “Verification of proposed design methodologies for effective width of slabs in slab-column frames.” ACI Struct. J., 94(2), 181–196.
Han, S. W., Kee, S.-H., Park, Y.-M., Lee, L.-H., and Kang, T. H.-K. (2006). “Hysteretic behavior of exterior post-tensioned flat plate connections.” Eng. Struct., 28(14), 1983–1996.
Hawkins, N. M., Wong, C. F., and Yang, C. H. (1978). “Slab-edge column connections transferring high intensity reversing moment normal to the edge of the slab.” Progress Rep. on NSF Project No. ENV 72-03585, SM 78-1, Dept. of Civil Engineering, Univ. of Washington, Seattle.
Hwang, S. J., and Moehle, J. P. (1993). “An experimental study of flat-plate structures under vertical and lateral loads.” Rep. No. UCB/EERC-93-03, Univ. of California, Berkeley, Calif.
Luo, Y. H., and Durrani, A. J. (1995a). “Equivalent beam model for flat-slab buildings. Part I: Interior connection.” ACI Struct. J., 92(1), 115–124.
Luo, Y. H., and Durrani, A. J. (1995b). “Equivalent beam model for flat-slab buildings. Part II: Exterior connection.” ACI Struct. J., 92(2), 250–257.
Luo, Y. H., Durrani, A. J., and Conte, J. P. (1994). “Equivalent frame analysis of flat plate buildings for seismic loading.” J. Struct. Eng., 120(7), 2137–2155.
Moehle, J. P., and Diebold, J. W. (1985). “Lateral load response of flat plate frame.” J. Struct. Eng., 111(10), 2149–2165.
Morrison, D. G., Hirasawa, I., and Sozen, M. A. (1983). “Lateral-load test of RC slab–column connection.” J. Struct. Eng., 109(11), 2698–2714.
Pan, A. P., and Moehle, J. P. (1988). “Reinforced concrete flat plates under lateral loading: An experimental study including biaxial effects.” Rep. No. UCB/EERC88/16, College of Engineering, Univ. of California, Berkeley, Calif.
Park, Y.-M., Han, S. W., and Ryu, J.-H. (2007). “Comparison of seismic behaviors of interior joints in PT and RC flat plate systems.” Key Eng. Mater., 348–349, 741–744.
Robertson, I. N., and Durrani, A. J. (1990). “Seismic response of connections in indeterminate flat-slab subassemblies.” Structural Research at Rice, Rep. No. 41, Dept. of Civil Engineering, Rice Univ., Houston.
Vanderbilt, M. D., and Corley, W. G. (1983). “Frame analysis for concrete buildings.” Concr. Int.: Des. Constr., 5(12), 33–43.
Zee, H. L., and Moehle, J. P. (1984). “Behavior of interior and exterior flat plate connections subjected to inelastic load reversals.” Rep. No. UCB/EERC-84/07, College of Engineering, Univ. of California, Berkeley, Calif.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 135 • Issue 6 • June 2009
Pages: 743 - 750
Copyright
© 2009 ASCE.
History
Received: Jan 15, 2008
Accepted: Jan 20, 2009
Published online: May 15, 2009
Published in print: Jun 2009
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