Effects of wind-induced vibrations in tall buildings on human balance and risk of falls

The rise in demand for housing in large cities has resulted in the construction of increasingly tall and slender buildings which are susceptible to wind-induced vibrations. Such vibrations may affect human balance and even put vulnerable occupants at risk of falls. Issues such as these are not currently considered in design guidelines, which could result in drastic social and economic consequences. To address this concern, a pilot study was conducted at the University of Bath's VSimulator facility to experimentally investigate the impact of wind-induced vibrations in tall buildings on human balance. Four young and healthy adults were exposed to synthesised bi-directional 'wind-induced' vibrations with a building natural frequency of 0.2-0.5Hz, peak factor of 3.5 and peak acceleration magnitudes of 0, 5 and 10 milli-g, while performing various tasks. Their performance was assessed by a test administrator, and they were also asked to carry out a self-reflection questionnaire to assess their level of motion sickness and general discomfort after each round of testing. Results from the study showed a consistent positive correlation between increasing acceleration magnitude and loss of balance in participants. An increase in effort required to maintain balance was observed, as well as a slight increase in motion sickness and general discomfort at 10 milli-g. It was also found that factors such as fatigue and practice/learning significantly affect the performance of occupants. By extending this study, a 'risk' threshold of vibration could be established, contributing to the development of guidelines that enable the design of safer and more suitable tall buildings for individuals susceptible to falls.