Abstract
It is important to grasp damping ratio on earthquake resistant design and wind resistant design. This paper describes the dynamic characteristics concerning a super high rise reinforced concrete stack based on vibration measurement data. The object stack is 100m height. Vibration measurement is performed twice. The first mode damping ratio in the state of construction of external structure and installation of internal ducts for smoke exhaustion are calculated. The relations between the first mode damping ratios and the state of structure are considered. Moreover, the first mode damping ratios in microtremor and in free vibration waves employing man power excitation are calculated. The relations between the first mode damping ratios and the amplitude are considered. In conclusion, the evaluated damping ratios are less than 1.0%. The damping ratio increased 30% as the amplitude increases 100 times than that in microtremor.
