Two aseismic hybrid control systems recently proposed for protecting tall buildings against strong earthquakes are investigated and evaluated. The hybrid control system consists of a base isolation system connected to either a passive or active mass damper. The base isolation system, such as elastomeric bearings, is used to decouple the horizontal ground motions from the building, whereas the mass damper, either active or passive, is used to protect the safety and integrity of the base isolation system. The per formance of the proposed hybrid control systems is compared with that of an active control system. It is shown from the theoretical/numerical investigations that the proposed hybrid control systems are very effective in reducing the response of tall buildings under strong earthquakes. Likewise, the practical implementation of such hybrid control systems is easier than that of an active control system alone.

Recently, increasing interest has been shown in structural safety design using active and hybrid control systems. This interest is driven by the rapid development of intelligent control systems, advanced sensor technology, signal processing, and successful applications in the control of large flexible space structures. This paper focuses on the potential and application of advanced control technology in land-based civil structures for safety protection against natural hazard forces such as winds and earthquakes. An assessment of the state-of-the-art in structural control technology that involves multiple, diverse fields is made in this paper, and, on this basis, an integrated comprehensive research program is outlined. Treating input forces as random loads—one of the most important aspects of structural control problems, e.g., their stochastic nature and implications in the formulation, solution, and practical implementation process-are highlighted. ,1. of INTELL.