Human perception of wind-induced tall building motions

In addition to strength and safety requirements, wind-induced building motion can interfere with building occupants' daily activities and hence occupant comfort is a critical design consideration, particularly for tall and slender buildings constructed in regions of high winds. Human response to motion is a complex mix of psychological and physiological factors, including tactile, vestibular, proprioceptive, kinaesthetic, visual and auditory cues, and visual-vestibular interaction. The response of individuals to single degree-of-freedom sinusoidal motion, on which most previous research using a motion simulator has been based, may be potentially quite different to the narrow-band random motion typical of wind-induced tall building motion. There is limited information available on the effects of this low-frequency narrow-band random motion on cognitive efficiency and mental performance. Although occupant comfort may govern the design of buildings ranging from less than 100 m to greater than 500 m in height with vastly different natural frequencies of vibration, many designers have consistently used the same frequency independent criteria, overlooking frequency-dependent criteria such as ISO-6897 [1]. Very little information has been gathered to clearly demonstrate the physiological response of people at the low natural frequencies typical of modern tall buildings and frequency dependence remains a contentious issue. This paper outlines some results acquired from experiments involving the response of human test subjects experiencing uni-axial and bi-axial random motion at frequencies ranging from 0.125 Hz to 1.00 Hz, using a purpose-built motion simulator in the CLP Power Wind/Wave Tunnel Facility (WWTF) at The Hong Kong University of Science and Technology (HKUST) that aims to address the key issues in designing for occupant comfort.