Seismic Response of RC Buildings with Inelastic Floor Diaphragms
Publication: Journal of Structural Engineering
Volume 117, Issue 4
Abstract
The in‐plane flexibility of floor‐slab systems has been observed to influence the seismic response of many types of reinforced concrete buildings. The assumption of rigid floor diaphragms is often used to simplify engineering analyses without significant loss in the accuracy of seismic response prediction for most buildings. However, for certain classes of structures, such as long and narrow buildings (especially with dual‐braced lateral load‐resisting systems), and buildings with horizontal (T‐ or L‐shaped) or vertical (setbacks or cross‐walls) offsets, the effect of diaphragm flexibility cannot be disregarded. Moreover, if the floor slab panels experience cracking or yielding due to pronounced in‐plane distortions, the seismic response of the entire building system may be significantly altered. This paper presents an simplified macromodeling scheme to incorporate the effect of inelastic floor flexibility in the seismic response analysis of RC buildings. The slab model includes effects of both in‐plane flexure and shear. The inelastic behavior of diaphragms is emphasized through a study of narrow rectangular buildings with end walls. The study shows that the in‐plane deflections of floor slabs impose a larger demand on strength and ductility of flexible frames than predicted values using the assumption of rigid or elastic slabs. These demands may in turn lead to a failure of the gravity‐load supporting system. A quantitative estimate of this effect is presented in terms of the floor aspect ratios.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Applied Technology Council. (1984). “Tentative provisions for the seismic regulations of buildings.” ATC‐3‐06, Applied Technology Council, Palo Alto, Calif.
2.
American Concrete Institute. (1986). “Building code requirements for reinforced concrete.” AC1‐318‐83, American Concrete Institute, Detroit, Mich.
3.
American National Standards Institute. (1982). “Minimum design loads for buildings and other structures.” ANSI‐A, ANSI A58.1, American National Standards Institute, New York, N.Y.
4.
Aktan, A. E., and Nelson, G. E. (1988). “Problems in predicting seismic responses of RC buildings.” J. Struct. Engrg., ASCE, 114(9), 2036–2056.
5.
Blume, J. A., Sharpe, R. L., and Elsesser, E. (1961). A structural dynamic investigation of fifteen school buildings subjected to simulated earthquake motion. Division of Agriculture, Sacramento, Calif.
6.
Button, M. R., Kelly, T. E., and Jones, L. R. (1984). “The influence of diaphragm flexibility on the seismic response of buildings.” 8th WCEE, Vol. IV, San Francisco, Calif.
7.
Chen, S.‐J. (1986). “Reinforced concrete floor slabs under in‐plane monotonic and cyclic loading,” thesis presented to Lehigh University, at Pennsylvania, Pa., in partial fulfillment of the requirements for the degree of Doctor of Philosophy.
8.
COMBAT. (1983). Comprehensive building analysis tool, Computech Engineering Services, Inc., Berkeley, Calif.
9.
International Conference of Building Officials. (1985). Uniform Building Code (UBC), Int. Conf. of Building Officials, Whittier, Calif.
10.
Jain, S. K. (1984). “Seismic response of buildings with flexible floors.” J. Engrg. Mech., ASCE, 110(1), 125–129.
11.
Jain, S. K., and Jennings, P. (1985). “Analytical models for low‐rise buildings with flexible floor diaphragms.” Earthquake Engrg. Struct. Dyn., 13, 225–241.
12.
Kabeyasawa, T., Shiohara, H., Otani, S., and Aoyama, H. (1983). “Analysis of the full scale seven story reinforced concrete test structure.” J. Faculty of Engrg., Univ. of Tokyo, Tokyo, Japan, 27(2).
13.
Karadogan, H. F., Nakashima, M., Huang, T., and Lu, L. W. (1978). “Static and dynamic analysis of buildings considering the effect of floor deformation—A state‐of‐the‐art survey.” Fritz Engineering Laboratory Report No. 422.2, Lehigh University, Pennsylvania, Pa.
14.
Kunnath, S. K., Reinhorn, A. M., and Park, Y. J. (1990). “Analytical modeling of inelastic seismic response of RC structures.” J. Struct. Engrg., ASCE, 116(4), 992–1017.
15.
Lee, D.‐G., and Moon, S.‐K. (1989). “Analysis of multistory building structures with flexible floor diaphragms.” Proc., 2nd East‐Asia Pacific Conf. on Struct. Engrg. and Const., Chiang Mai, Thailand, Vol. 1, 799–804.
16.
Liu, D., and Yang, C. (1988). “The effect of stiffness degradation of shear wall and floor horizontal deformation on the flame‐shear wall buildings.” Proc., 9th World Conf. on Earthquake Engineering, Tokyo, Japan, Vol. 6, 17–22.
17.
Nakashima, M., Huang, T., and Lu, L.‐W. (1981). “Experimental study of seismic behavior of reinforced concrete floor systems: Beam supported slab structures.” Fritz Engineering Laboratory Report, No. 422.7, Lehigh Univ., Pennsylvania, Pa.
18.
Nakashima, M., Huang, T., and Lu, L.‐W. (1982). “Experimental study of beam‐supported slabs under in‐plane loading.” ACI Struct. J., (Jan.‐Feb.), 59–65.
19.
Park, Y. J., Reinhorn, A. M., and Kunnath, S. K. (1987). “IDARC: Inelastic damage analysis of reinforced concrete frame—Shear‐wall structures.” Technical Report No. NCEER‐87‐0008, National Center for Earthquake Engineering Research, State Univ. of New York at Buffalo, Buffalo, N.Y.
20.
Reinhorn, A. M., Kunnath, S. K., and Panahshahi, N. (1988). “Modeling of RC building structures with flexible floor diaphgrams (IDARC2).” Technical Report No. NCEER‐88‐0035, National Center for Earthquake Engineering Research, State Univ. of New York at Buffalo, Buffalo, N.Y.
21.
Roper, S. C., and Iding, R. H. (1984). “Appropriateness of the rigid floor assumption for buildings with irregular features.” Proc., 8th World Conf. on Earthquake Engineering, San Francisco, Calif., 751–758.
22.
Suto, F., and Asayama, S. (1988). “Experimental considerations on earthquake behaviors of large long strip‐type of actual structures.” Proc., 9th World Conf. on Earthquake Engrg., Tokyo, Japan, Vol. V, 503–508.
23.
Unemori, A. L., Roesset, J. M., and Becker, J. M. (1980). “Effect of in‐plane floor slab flexibility on the response of crosswall buildings.” Reinforced concrete buildings subjected to wind and earthquake forces, ACI‐Special Publication No. 63, American Concrete Institute, Detroit, Mich.
Information & Authors
Information
Published In
Copyright
Copyright © 1991 ASCE.
History
Published online: Apr 1, 1991
Published in print: Apr 1991
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.