Is Your Supplementary Damping Going to Do What You Want It To?

Roy Denoon
Vice President
CPP Wind Engineering and Air Quality Consultants, Denver

Supplementary damping in tall buildings is most commonly specified for the purposes of improving occupant comfort, or more pragmatically, reducing the potential for significant complaints to the building owners, builders, developers, and operators, and the risks associated with such complaints. However, the relative risks are rarely discussed fully, or understood, within the design and client teams during the design and construction process. This presentation examines the risks, and how to account for them through design.

Relatively opaque acceleration response guidelines are generally used as criteria for when dampers should be specified. The first part of the presentation examines the origins of these guidelines and how they might be interpreted in relation to expected building occupancy and geographical location. Common misconceptions will also be addressed. The second part of the presentation discusses how to ensure that any damping system that is specified will perform as anticipated. Often, as-built structural properties differ significantly from design values and these can affect both the predicted accelerations and the damper performance. The interplay between these factors is discussed, along with how to minimize cost and construction schedule impacts when this occurs. The final part of the presentation discusses the role of dampers and damping specification within a performance-based wind and structural engineering design environment. In the next few years, there will be a number of new publications setting a framework for performance-based wind engineering. An overview of current thinking on how supplementary damping will fit into these publications is presented.