Field test of resonant frequency monitoring utilizing background vibration in various buildings
* Presenting author
A number of big intermittent aftershocks often follows a great earthquake. Even if a certain building escapes from the collapse due to the first main quake, there is no guarantee that the building can survive from the aftershocks. If it is possible to monitor the condition of the buildings constantly using some faint random vibration caused by background vibration such as wind, weak earthquakes and traffic vibration, the safety will be more secured. The authors have proposed cumulative harmonic analysis that emphasizes the hidden resonances in a time-invariant transfer function, and conducted the experimental monitoring of the resonant frequency in an actual building from the analysis of the faint random vibration on the building caused by the background vibration. From the results of comparison with the measured values of the resonant frequency by an active diagnosis it is confirmed that the estimation of the resonant frequency by the proposed method obtains an accurate value only including few percent error. This report describes about the results of field tests on various buildings using the proposed method.