Use of Supplemental Damping Devices for Seismic Strengthening of Lightly Reinforced Concrete Frames

1. ABSTRACT Devices which can add damping and strengthen structural systems, without changes to the existing components, were found recently extremely useful in retrofitting lightly reinforced frames and other structures. Some damping devices were developed purposely for building structures, however, many more were adapted from use in other industries such as the military and aerospace. Damping devices can provide also supplemental stiffening and strength to structures that lack such properties, in most cases without altering the existing components. The use of such devices does not require major disturbances or loss of functions of the structures during retrofit. However, a good understanding of dampers contribution to enhancing the structures capacities and reducing the seismic demand is essential to the design process. This paper surveys the state-of-the-art of seismic retrofit design, the role of supplemental dampers in such design and the currently available damping devices. The paper summarized some validation studies of use of devices for seismic retrofit and presents several implementations in actual buildings.