Seismic Protection of Existing Buildings with Tuned-Mass Control Systems

This paper illustrates the practical application of the tuned-mass control systems (TMCSs) in the seismic upgrade of existing buildings. In these cases, the interior of a building is usually not objective to modification. The TMCS consist of an additional mass, arranged at the top elevation of a structure, for example, on top of the roof. Thus, utilization of the building can continue during the retrofitting measures. The mass is elastically connected with the structure. Dampers are arranged between the mass and the structure to increase the internal damping ratio. Such passive control systems can be used to improve the seismic behaviour of a building in regard to resulting displacements, accelerations and internal stresses during an earthquake. The successful retrofit of the government building Palatul Victoria in Bucharest, Romania, is presented as an actual example. Here, the consolidation strategy consists of a combination of conventional strengthening measures and the application of the specially developed TMCSs. The determination of the parameters of the TMCSs is discussed. Selected results of the numerical calculations demonstrate the efficiency of the measures. Pictures of the installed system illustrate the general applicability of the TMCSs.