Civil Engineering Reference
In-Depth Information
Figure 9.16
Two-degree-of-freedom
representation of a tuned mass damper.
Figure 9.17
Tuned sloshing damper.
Tuned mass damper systems similar to those in the Citycorp Center have been installed in
both the John Hancock Building, Boston, and in the Chiba Port Tower. In the case of the
latter structure, the system has been installed to mitigate vibrations due to both wind
(typhoon) and earthquake. Adjustable coil springs are used to restrain the moving mass,
which is supported on frames sliding on rails in two orthogonal directions.
The current (2006) world's tallest building, Taipei 101, has a pendulum type TMD,
consisting of a 660 tonne spherical steel mass, suspended at a length to tune it to the
building frequency of 0.14 Hz. It is claimed to reduce the accelerations at the top of the
building by 30-40%.
The performance of tuned mass dampers in tall buildings and towers under wind
loading has been reviewed by Kwok and Samali (1995).
