This paper describes forced vibration tests and microtremor measurements performed at 9-story actual building before and after a steel beam were damaged artificially. The damage detection through these measurements data is applied. It is shown that (1) It is difficult to detect the damage based on the horizontal response change at each stories using forced vibration tests and microtremor measurements data; (2) It is possible to detect the damage based on the vertical response change on damaged beam using forced vibration tests data.
