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Tall buildings are one of the few products of engineering whose design cannot be practically tested in full-scale prior to construction and thus relies solely upon analytical and scaled models. Although these models are based upon fundamental mechanics and years of research and experience, they have yet to be systematically validated in full-scale and so the nature of the project still requires a leap of faith into the construction stage. Recently available technological advances enable full-scale monitoring and real-time health monitoring systems to validate design practices and evaluate tall building performance on multiple levels and under various types of wind excitations. As the height and prevalence of high-rise developments continues to grow worldwide, a deeper understanding of their in-situ behavior is increasingly critical to advance the design state-of-the-art, thus motivating the use of cutting edge monitoring systems and subsequent data analyses. |
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SmartSync: Real-Time Health Monitoring Using Local Area Networks
Civil Infrastructure Systems rarely employ advanced evaluation and diagnostic technologies to for maintenance and in-situ verification of performance. One of the reasons for this is the barrier that the technology presents to end users and the challenges in deploying distributed sensor networks over large complex systems. This project introduces a unique prototype system for Structural Health Monitoring, SmartSync, which utilizes the building’s existing Internet backbone as a system of “virtual” instrumentation cables to permit modular and largely “plug-and-play” deployments. The system enables a scalable, robust and automated approach to monitoring tall and complex structures. With its installation in Burj Khalifa, the system demonstrates how health monitoring solutions can be practically delivered in even the world’s tallest building.
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Chicago Full-Scale Monitoring Program: Full-Scale Validation of Tall Building Design Practice
A unique partnership between academia, design firms and commercial wind tunnel testing facilities, the Chicago Full-Scale Monitoring Program represents the first systematic validation of tall building performance in the United States, comparing full-scale data against the wind tunnel test predictions used in their design. With high-sensitivity accelerometers, sub-centimeter accuracy Global Positioning Systems, and anemometers, the program currently documents the dynamic responses of five tall buildings representing a diverse array of materials and structural systems in Chicago, Seoul, and Dubai. Analysis of in-situ dynamic properties from this data has also enabled comparison of in-situ and predicted frequency and damping characteristics, underscoring a number of important considerations in the finite element modeling of various lateral systems.
[Fact Sheet | www | Publications] |
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Transient Dynamics of Tall Buildings Transient wind events are not considered in wind tunnel studies and do not factor in to habitability design of tall buildings, despite the fact that, outside of hurricanes, the most severe wind events in the US are those that result from gust front and thunderstorm activities. Characterized by rapid changes in wind speed and direction, transient winds provide impulsive stimuli to buildings, capable of exciting multiple modes with their broadband energy. Full-scale monitoring and anecdotal evidence have verified that these events occur regularly and are capable of producing accelerations that exceed those generated by stationary events at comparable wind speeds, and should be considered in the design of tall buildings. [Fact Sheet | Publications] |
Characterization and Modeling of Energy Dissipation in Common Structural Systems
Damping has a significant effect on the acceleration responses of dynamically sensitive structures, making its accurate estimation in the design stage critical. Because damping is dependent on many variables and complex mechanisms that are not yet fully quantifiable in the design stage, current design practices estimate damping based on the building’s primary construction material and little else, often resulting in an un-conservative design. However, full-scale observations demonstrate that the structural system’s dominant deformation mechanism - frame racking vs. cantilever action – plays a significant role in energy dissipation capability, and can serve as a robust parameter for improved predictive viscous damping models.
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Occupant Comfort Criteria for Tall Buildings
Habitability limit states often govern the design of tall structures, as wind-induced accelerations increase and become more perceptible to occupants. These limit states are determined from occupant comfort criteria, which have been established based on motion simulator studies that cannot capture environmental factors such as occupancy type, visual and audio cues. The perception threshold of a group, for example, can be lowered when a highly sensitive person vocally triggers others’ awareness of motion, though educating occupants on the normalcy of tall building motion may increase their comfort threshold. Through full-scale data and an online survey, this project seeks a non-intrusive approach to habitability assessment of monitored structures to establish more appropriate occupant comfort criteria for tall buildings.
[Fact Sheet | Abstract | Publications]
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e-Design Aids for Tall Buildings Under Wind
[Fact Sheet | Abstract | www | Publications]
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ASCE Tall Buildings Committee [Fact Sheet | Abstract | www | Publications]
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SOM Traveling Fellowship in Structural Engineering
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CONTACT Lab Facility: * University of Notre Dame, 107 Cushing Hall, Notre Dame, IN 46556 USA ( 574.631.3914 : dynamo@nd.edu Dr. Kijewski-Correa: * University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 USA ( 574.631.2980 : tkijewsk@nd.edu
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