Michael R. Willford

This paper describes new concepts for the structural design of high‐rise buildings, in which a system is introduced to increase the dependable structural damping by a factor of 5–10. By so doing the dynamic response of the building to wind effects (buffeting and vortex shedding) is virtually eliminated, leading to substantially reduced lateral design forces and assured occupant comfort. Substantial reductions in structural member size and construction cost savings can be realized in many cases. This may significantly improve the economic viability and sustainability of a development. The paper describes some means by which high levels of damping may be achieved and is illustrated by an implementation on a building, currently under construction, subjected to wind and seismic excitation. Copyright © 2007 John Wiley & Sons, Ltd.

The increasing use of high strength materials, modern architectural expression and the desire for high-tech building environments has led to an increasing need to consider vibration performance as a key design objective for buildings and other structures. Human footfall is a significant source of vibration and if its effects are not assessed accurately during the design of a facility the workspaces may be rendered unusable for sensitive equipment or uncomfortable for occupants. In view of the importance of achieving an acceptable vibration environment in modern facilities it is perhaps surprising that the design methods employed by most structural and vibration engineers comprise very simple and semi-empirical hand calculations based on research available in the 1970s. In order to provide clients with greater confidence in the performance of their structures Arup has developed new and more accurate `performance based' prediction procedures incorporating recent comprehensive experimental research into footfall forces, and taking advantage of the capabilities of modern design-office computer software. The new methods are not limited by the approximations and inaccuracies inherent in the old empirical approaches, and extensive calibration against field measurements has shown them to be far more reliable than other methods currently in use. This new approach can bring substantial cost benefits in some cases as well as reduction in risk through accurate quantification of performance. This paper describes the methodology in detail and compares with predictions from other methods and measured data.