Affiliation:
1. Department of Civil, Chemical, Environmental, and Materials Engineering—DICAM, University of Bologna, Viale del Risorgimento 2, 40136 Bologna, Italy
Abstract
Equivalent viscous damping plays a central role in displacement-based design procedures. In this paper, approaches for estimating the equivalent viscous damping of RC frame buildings are proposed. At first, the analytical formulation of Blandon and Priestley was analysed, and then a calibration of the coefficients of this formulation was performed. Compared with the work of Blandon and Priestley, a larger set of synthetic accelerograms, related to different types of soil and different intensities, and a wider range of the effective periods were considered. In particular, two different sets of parameters are proposed: the first is usable in the case of spectra obtained numerically (approach 1), and the second is usable in the case of code-based spectra and damping modification factor (approach 2). To test the performed calibration and to compare the considered formulations (i.e., the proposed and literature equations), the direct displacement-based design procedure has been applied to three case studies of reinforced concrete frame structures, and then pushover and nonlinear time-history analyses have been performed. The results show that the use of the calibrated parameters (for both the considered approaches) has determined more conservative results, in terms of design base shear and maximum drift from NLTH. Moreover, the average displacement profiles and the inter-storey drifts obtained from time-history analyses for the frames designed with the calibrated parameters match better the design profile.
Reference49 articles.
1. Myths and Fallacies in Earthquake Engineering—Conflicts between Design and Reality;Priestley;Bull. N. Z. Soc. Earthq. Eng.,1993
2. Priestley, M.J.N. (February, January 30). Performance based seismic design. Proceedings of the 12th World Conference on Earthquake Engineering, Auckland, New Zealand. paper no. 2831.
3. Priestley, M.J.N. (2003). Myths and Fallacies in Earthquake Engineering, revisited. The 9th Mallet Milne Lecture, IUSS Press.
4. The limitations and performances of different displacement based design methods;Sullivan;J. Earthq. Eng.,2003
5. Muljati, I., Asisi, F., and Willyanto, K. (2015, January 15–18). Performance of force based design versus direct displacement design in predicting seismic demands of regular concrete special moment resisting frames. Proceedings of the 5th International Conference of Euro Asia Civil Engineering Forum, Surabaya, Indonesia.