Evaluation of Torsional Provisions in Seismic Codes
Publication: Journal of Structural Engineering
Volume 117, Issue 12
Abstract
The effects of plan asymmetry on the earthquake response of code‐designed, one‐story systems are identified with the objective of evaluating how well these effects are represented by torsional provisions in building codes. The earthquake‐induced deformations and ductility demands on resisting elements of asymmetric‐plan systems, designed according to several different codes, are compared with their values if the system plan were symmetric. The presented results demonstrate that the design eccentricity in building codes should be modified in order to achieve the desirable goal of similar ductility demands on asymmetric‐plan and symmetric‐plan systems. The design eccentricity should be defined differently for elastic and inelastic systems; in the latter case, it should vary with the design force level or anticipated degree of inelastic action. However, it does not appear possible to reduce the additional element deformations due to plan asymmetry by modifying the design eccentricity; these deformations should be provided for in building design.
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References
1.
Chandler, A. M., and Hutchinson, G. L. (1987). “Evaluation of code torsional provisions by a time history approach.” Earthquake Engrg. Struct. Dyn., 15(4), 491–516.
2.
Esteva, L. (1987). “Earthquake engineering research and practice in Mexico after the 1985 earthquakes.” Bull. New Zealand Nat. Soc. Earthquake Engrg., 20(3), 159–200.
3.
Goel, R. K. and Chopra, A. K. (1990). “Inelastic earthquake response of one‐story, asymmetric‐plan systems. Report No. UCB/EERC‐90/14, Earthquake Engineering Research Center, University of California, Berkeley, Calif.
4.
Gomez, R., and Garcia‐Ranz, F. (1988). “The Mexico earthquake of September 19, 1985—Complementary technical norms for earthquake resistant design.” Earthquake Spectra, 4(3), 441–460.
5.
Humar, J. L. (1984). “Design for seismic torsional forces.” Can. J. Civ. Engrg., 11(2), 150–163.
6.
International Association for Earthquake Engineering, Earthquake resistant regulations. A world list, (1988). Tokyo, Japan.
7.
Irvine, H. M., and Kountouris, G. E. (1980). “Peak ductility demands in simple torsionally unbalanced building models subjected to earthquake ground excitation.” Proc. Seventh World Conf. Earthquake Engrg., Istanbul, Turkey, 4, 117–120.
8.
Kan, C. L., and Chopra, A. K. (1981). “Torsional coupling and earthquake response of simple elastic and inelastic systems.” J. Struct. Div., ASCE, 107(8), 1569–1588.
9.
Pekau, O. A., and Rutenberg, A. (1987). “Evaluation of the torsional provisions in the 1985 NBCC.” Proc. Fifth Canadian Conf. Earthquake Engrg., Ottawa, Canada, 739–746.
10.
Poole, R. A. (1977). “Analysis for torsion employing provisions of NZRS 4203:1974.” Bull. New Zealand Nat. Soc. Earthquake Engrg., 10(4), 219–225.
11.
Rutenberg, A., and Pekau, O. A. (1983). “Earthquake response of asymmetric buildings: A parametric study.” Proc. Fourth Canadian Conf. Earthquake Engrg., Vancouver, Canada, 271–281.
12.
Rutenberg, A., and Pekau, O. A. (1987). “Seismic code provisions for asymmetric structures: A reevaluation.” Engrg. Struct., 9(4), 255–264.
13.
Rutenberg, A., and Pekau, O. A. (1989). “Seismic code provisions for asymmetric structures: Low period systems.” Engrg. Struct., 11(2) 92–96.
14.
Rutenberg, A., Shohet G., and Eisenberger, M. (1989). “Inelastic seismic response of code designed asymmetric structures.” Fac. Pub. 303, Technion, Israel Institute of Technology, Haifa, Israel.
15.
“Tentative provisions for the development of seismic regulations for buildings.” (1978). ATC3‐06, Applied Technological Council, Palo Alto, Calif.
16.
Tso, W. K., and Hongshan, Y. (1990). “Additional seismic inelastic deformation caused by structural asymmetry.” J. Earthquake Engrg. Struct. Dyn., 19(2), 243–258.
17.
Tso, W. K., and Meng, V. (1982). “Torsional provisions in building codes.” Can. J. Civ. Engrg., 9(1), 38–46.
18.
Veletsos, A. S., and Vann, W. P. (1971). “Response of ground‐excited elastoplastic systems.” J. Struct. Div., ASCE, 97(4), 1257–1281.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 117 • Issue 12 • December 1991
Pages: 3762 - 3782
Copyright
Copyright © 1991 ASCE.
History
Published online: Dec 1, 1991
Published in print: Dec 1991
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