Abstract
This paper describes the dynamic characteristics based on microtremor measurement data concerning a high-rise steel building. The object building which was completed in October 1998 is 120m height and rectangular plan. Microtremor measurement is continued periodically in the building. The acceleration and velocity of measurement data in two horizontal directions and torsional direction are analyzed for natural frequencies and damping ratios on 1st mode to 4th mode. The changes along passages and the dispersions of those dynamic characteristics in microtremor are studied. And the relations between vibration amplitude and damping ratios in free vibration waves by manpower excitation are discussed.
