A dynamic test of a four-story reinforced concrete building

Forced vibration tests were conducted on a four-story reinforced concrete building. Deflections and accelerations were produced which approached the magnitude of those which occur during strong-motion earthquakes. Damping values were calculated from the resonance curves obtained. The results show that the total damping in the structure is small and that the damping apparently increases with increasing amplitude of motion. Within the accuracy of the measurements the damping was independent of the frequency of the motion.