Department of Architectural Engineering

ABSTRACT

The presentation “Design and Control for Floor Vibrations” has two distinct foci as suggested by the title. The design portion will describe the nature of floor vibration, the AISC code requirements for floor systems, and a bit of recent history in the development of floor vibration criteria for walking excitation. Also to be described is a new criterion for walking vibration that is considered the current “state-of-the-art”. This criterion is found in the recently published AISC Design Guide 11: Floor Vibrations Due to Human Activity. To understand the derivation of this criterion, a foundation in structural dynamics will be presented followed by a description of the criterion itself. Finally, some compelling research needs, with respect to further developing floor vibration design criteria, will be presented.

Perhaps one day vibration criteria for floor systems will mature to a point where repair measures will no longer be necessary. The current reality, however, is that serviceability limit states are often neglected or are a source of uncertainty in the design of a floor systems. The result is often an unacceptable floor in need of repair. Traditional methods for improving floor vibration characteristics vary widely in the cost of implementation, obtrusiveness, and effectiveness and as such, these drawbacks compel researchers to search for alternative methods for controlling excessive floor vibrations. One method, currently in its final developmental stage, uses an actively controlled electro-magnetic proof-mass actuator to damp resonant floor vibrations. In this presentation, the theoretical concept of active control will be presented, followed by a discussion of its application to floor systems. Results illustrating the effectiveness of this method will be shown for several building floor systems. Finally, research issues remaining unresolved will be discussed.