Control of earthquake-induced torsional vibrations in asymmetric buildings

摘要

The performance of structures during past earthquakes has shown that asymmetric-plan buildings are especially vulnerable to earthquake damage due to excessive edge deformations resulting from coupled lateral-torsional motions. This investigation examined how supplemental viscous damping can be used to control these excessive deformations in asymmetric-plan buildings. It was found that symmetric distribution of supplemental damping devices in the building plan is not necessarily the best way to control excessive deformations in an asymmetric-plan building; a value of the damping eccentricity equal to the structural eccentricity in magnitude but opposite in algebraic sign leads to higher reduction. A larger reduction is also obtained by providing a larger value of the damping radius of gyration.