NCEER-89-0041 | 11/1/1989 | 136 pages
TOC: The table of contents is provided.
Keywords: System Response Investigations, Seismic Risk Assessment, Analytical Modeling, SUPER-ETABS, Structural Dynamics, and Tall Buildings.
Abstract: This report presents a study of three dimensional analytical modeling of buildings based on the computer program SUPER-ETABS. A 27-story reinforced concrete building with unsymmetric cores was simulated. First, a predictive analytical model was developed based on the engineering theory for member analysis of the cores. A series of forced-excitation dynamic tests were then conducted of the real building in the context of modal testing. Its global dynamic responses were measured to validate, improve, and identify the parameters of the predictive analytical model. The first nine frequencies and the corresponding 3D normalized mode shapes were measured by model testing. After correlating the measured results with those from the predictive ETABS model, this had to be revised. An improved model, termed "simulative ETABS model," was hence developed. The frequencies, mode shapes, and flexibilities of predictive, measured, and simulative analytical models were compared, revealing an excellent correlation between the ETABS model and measured responses. This was accomplished without a rigorous adjustment of its parameters. The predictive model, however, was shown to have poor correlation with experiments, without any numerical adjustment of its parameters. This indicated the importance of experimental identification in evaluating existing buildings with unusual attributes.