Depreciation models to accelerate the building construction

Research that has been conducted by a team from the University of Bristol and published in the journal Structures claims that high-rise buildings are thoroughly constructed to withstand wind forces. They argue that accurately estimating damping, which involves dissipating energy to control vibratory motion such as noise and mechanical vibration, presents several challenges in high-rise buildings.

In general, a structure's response to dynamic loading is greatly influenced by its damping characteristics. While mathematical models of damping have been developed, they often fail to accurately represent the physical processes involved. This has led to the predominance of empirical models that cannot be easily generalized to all building types. This research aims to address this limitation by studying damping.

Specifically, they examined the damping and natural frequency characteristics of a 150m tall building in London, UK, using full-scale wind-induced responses tracked by a minimal tracking system. Moreover, the team employed three accelerometers and an ultrasonic anemometer to measure wind-induced vibrations and wind conditions at the structure's top over a year-long period.

Natural frequencies and damping ratios were derived from acceleration power spectral densities and correlated with wind data. Various environmental factors, e.g. wind magnitude and direction relative to building motion, were examined. A finite element model of the tower was used to support experimental observations.

Lead author Daniel Gonzalez-Fernandez from Bristol's School of Civil, Aerospace, and Design Engineering stated that they consider multiple parameters such as amplitude, time, wind speed, and direction. They concluded that while amplitude and time affect the natural frequencies, amplitude has the most significant impact on the damping ratio.

Given that wind effects pose a significant concern in tall building design, uncertainties arise, particularly regarding damping and its sources. Furthermore, predictive models for these complex systems require validation. In-situ measured mode characteristics, like natural frequencies and modal damping, serve as crucial resources for updating models. Daniel emphasized that for tall buildings, occupant comfort is directly impacted by wind-induced sway, which can affect daily activities. He continued, pointing out that these insights may inform future designs to mitigate vibration's adverse effects, enhancing structural performance, and reducing failure risks.