Analysis of wind-induced vibrations in high-rise buildings

Buildings are getting taller due to increased urbanisation and densification of cities. More advanced construction methods and the desire to construct impressive buildings is also supporting the trend. Due to their inherent slenderness resulting in low eigenfrequencies, these buildings are susceptible to wind-induced vibrations which can be highly disturbing for occupants. Already barely perceivable acceleration levels within the low-frequency range relevant to whole-body vibrations can cause nausea and discomfort, while high acceleration levels can cause alarm and fea r amongst the occupants. The paper summarises acceptable acceleration levels in high -rise buildings (here referred to as buildings over 200 m in height) stated in different building codes and previous work on the subject. Accelerations of a high-rise building subjected to wind-loads are evaluated using a full numerical model and one reduced with Ritz-vectors and the results are compared. The paper focuses on wind-load dynamics in early stages of the design process, with an intent to give an indication of the dynamic properties of a building.