UBC Theses and Dissertations
Model updating of a 48-storey building in Vancouver using ambient vibration measurements Lord, Jean-François
This study focused on the One Wall Centre, a 48-storey high building located in downtown Vancouver, British Columbia. It is currently the highest building in Vancouver, and it is the only structure in the region that makes use of tuned liquid column dampers to reduce vibrations due to wind. The "true" dynamic response of the One Wall Centre is of great interest to structural engineers because of the unusual elliptical shape of the concrete shear core, which could present a challenge for modelling. Ambient vibration testing was conducted on the One Wall Centre in order to determine its modal characteristics. Such characteristics included the natural periods of the building, their corresponding mode shapes and damping ratios. The analysis of the ambient vibration data was performed using a state-of-the-art modal identification technique in the frequency domain and a second technique in the time domain. The natural periods and mode shapes of the One Wall Centre were predicted analytically using a linear-elastic finite element (FE) computer model of the building. Only the main lateral load-resisting system components were modelled, which included the reinforced concrete shear core, the outrigger columns and outrigger beams. It was found that the FE model was more flexible than the actual structure. In order to achieve a better match between the analytical and experimental dynamic responses, the FE model was updated using two techniques: manual model updating and automated model updating. The main change to the FE model from the manual model updating was the inclusion of the stiffness contribution of the architectural components, such as the outside windows and partition walls. The intent of the automated technique was to determine the sensitivity of the FE models to variations in element physical properties (Young's modulus, material mass density, moment of inertia and thickness of elements). An excellent match was achieved between the analytical and experimental results after manual and automated updating of the FE models.
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