Wind tunnel verification of actively controlled high-rise building in along-wind motion

Recently, the newly developed technology towards lighter and more strengthened material has facilitated more and more construction of high-rise buildings in many urban areas where the efficiency of space usage is demanding. Though the strength capacity of these buildings is adequate for safety requirement under wind excitation, the stiffness lessened might cause excessive displacements and accelerations on which building serviceability and comfort of occupants depend. In the last decade, many research efforts have demonstrated that the use of structural control is able to achieve remarkable results in reducing the wind-induced vibration for high-rise buildings. However, most of them are accomplished using numerical simulation. In this paper, a feasible and reliable design process for active control is proposed through wind tunnel tests. A four degree-of-freedom scaled (1:300) model of a high-rise building equipped with active mass driver is constructed on a wind tunnel to experimentally verify its applicability for wind-induced along-wind motion. A system identification scheme, which is capable of taking into account the interaction among wind, control device and structure, is presented to construct the nominal system. For the controller design, the advanced control strategy, linear quadratic Gaussian (LQG) method with acceleration feedback, is employed. From the experimental results, it is shown that the performance of the active controller following the design process proposed is remarkable in reducing the along-wind responses of high-rise buildings. Furthermore, despite of the fact that nominal system itself contains system uncertainty, the performance of active control using LQG control law remains quite promising and robust.