Vibration Characteristics of Steel-Framed House Based on Long-Term Seismic Observation Records and Microtremor Measurement

Abstract

In this paper, we examine the dynamic properties of an existing three-story steel-framed house based on the observation records obtained from seismic observations and microtremor measurement. As a result, it was concluded as follows. The first is that a decrease in the natural frequency and an increase in the damping constant, which are thought to be caused by earthquakes and secular changes, were observed. The second is that even within an earthquake, the natural frequency drops during periods of particularly large amplitude and then recovers. It is possible that these phenomena mainly depend on reversible phenomena such as friction between non-structural members. The third is that at the microtremor level, the natural frequency is higher and the damping constant is smaller than during the earthquake.