Tuned mass damper for reduction seismic and wind loads

Tuned mass dampers (TMDs) are used mainly for reduction of seismic and wind oscillations in high-rise buildings. It is well known that base isolation is ineffective in tall buildings. In general, TMDs can reduce seismic loads in tall building, but it needs a large mass of TMDs. In addition, TMDs cannot reduce vertical oscillations, which can be very destructive due to P-delta effect. This paper presents an engineering solution for mitigation of structural response caused by seismic excitations. The approach of using the upper part of the building as a TMD can significantly reduce horizontal accelerations and stresses in building elements up to 50 % along the entire height. In addition, the proposed TMD can significantly reduce vertical oscillations in a primary building up to 30 % in comparison with building without TMD. This solution can be used in both existing and new buildings. This solution does not require any additional mass and its transportation to the installation site. An optimization criterion for defining optimal TMD's properties was developed. The criterion is the objective function of maximum difference in accelerations of floors with and without TMD along the entire height. For analytical studies, matrix of stiffness that takes into account bending and sliding motions and dissipation matrix that takes into account damping ratio for soil, TMD constructions and constructions of the building were developed.