VIBRATION CONTROL OF TALL BUILDINGS USING MEGA SUBCONFIGURATION

An innovative vibration-control system is proposed to reduce the dynam ic response of tall buildings to wind and seismic loads. This system f akes advantage of the so-called megasubstructure configuration, which is especially popular in tall buildings. Substructures contained in th e megastructure serve as energy absorbers so that no additional mass i s required for the intended vibration control as seen in the conventio nal mass damper systems. The proposed system naturally resolves the di fficulties in augmenting damping capacities of tall buildings associat ed with the high rigidity and deformation in the dominant bending mode . Dynamic characteristics of the proposed control system including the frequency response and the energy flow are investigated. Optimal valu es of structural parameters such as the damping ratio and stiffness of the substructure are determined. The feasibility and effectiveness of this unique control system in improving human comfort and protecting structures under both wind and earthquake loads are demonstrated throu gh analytical and numerical analysis.