Validating Wind-Induced Response of Tall Buildings: Synopsis of the Chicago Full-Scale Monitoring Program

Abstract

Tall buildings are one of the few constructed facilities whose design relies solely upon analytical and scaled models, which, though based upon fundamental mechanics and years of research and experience, has yet to be systematically validated in full scale. In response to this need, through the combined efforts of members of academe, a design firm and a commercial wind tunnel testing laboratory, a program was initiated to monitor the full-scale response of representative tall buildings and compare this to the predicted response from wind tunnels and finite-element models used commonly in design. As part of this monitoring program, in situ periods and damping ratios over a range of response amplitudes are also being evaluated. This paper provides an overview of the monitoring program, which includes three tall buildings in the city of Chicago, details their instrumentation and modeling, and provides an example of the full-scale response data analyses being conducted.

Vibration-based monitoring of civil infrastructure: challenges and successes

“…With the lack of information about the performance of these structures, monitoring provides useful validation of predictions using wind-tunnels and supports better understanding of the loadresponse mechanisms (Kijewski-Correa et al, 2006;Kwon et al, 2010). …”

Wind-induced vibrations of buildings: role of transient events

“…This study will utilise acceleration data from an instrumented tall building that is part of the Chicago full-scale monitoring programme (Kijewski-Correa et al, 2006) to underscore some of the unique dynamics associated with tall building response to transient wind events, using a wavelet-based approach to system identification. While wavelets have been used previously by the authors to visualise transient features (Bentz and Kijewski-Correa, 2009a;Kijewski-Correa and Pirnia, 2007), this study takes the wavelet analysis a step further by actually performing system identification within the wavelet framework.…”

“…In particular, since there is no means to estimate damping effectively in the design stage, the earliest full-scale efforts were directed towards short-term monitoring of suites of buildings to develop damping databases (Davenport and Hill-Carroll, 1986;Jeary, 1986;Lagomarsino, 1993). Since then, monitoring efforts have grown increasingly long-term (Brownjohn et al, 1998;Li et al, 1998;Kijewski-Correa et al, 2006) with the objective of observing the structure under a range of wind events to validate the design process more systematically, especially in extreme events such as typhoons (Li et al, 2005;Xu and Zhan, 2001). In these studies, discrepancies between predicted and measured natural frequencies and damping ratios have been noted.…”

“…In these studies, discrepancies between predicted and measured natural frequencies and damping ratios have been noted. Particularly in newer reinforced concrete structures, natural frequencies have been observed to be higher in situ, owing to assumptions of cracking in the finite-element model development that have yet to be realised in service, or owing to differing material properties in situ (Kijewski-Correa et al, 2006). In other cases, discrepancies have indicated errant assumptions regarding the participation of gravity elements in the overall concrete lateral system (Erwin et al, 2007) or a failure adequately to capture steel connection flexibility (Kijewski-Correa et al, 2005).…”

System Identification of Constructed Facilities: Challenges and Opportunities across Hazards

“…However, reinforced concrete interactive systems were found to be stiffer in-situ (by up to 25%), which may be attributed to differences in in-situ modulus of elasticity or model stiffness reductions due to cracking that has yet to be observed in the service life of the building. Conversely, interactive steel systems deviated from FEM predictions, yielding longer in-situ periods by approximately 10%, potentially due to unmodeled panel zone deformations [Kijewski-Correa et al, 2006]. These full-scale investigations have also formulated hypotheses surrounding energy dissipation capabilities tied to dominant deformation mechanisms in these systems [Bentz and Kijewski-Correa, 2008].…”