Evaluation of Structural Health Monitoring Results utilizing Environmental Noise

A number of big intermittent aftershocks often follow a great earthquake. Even if a building could avoid collapse by the first main quake, there would be no guarantee that the building can survive from the aftershocks. However, if it is possible to monitor the condition of the building constantly using some faint random vibration caused by environmental noise such as wind, weak earthquakes and traffic noise, the safety of the victims should be more secured. The author has proposed a cumulative harmonic analysis that emphasizes the hidden resonances in a time- invariant transfer function and has also applied the method to structural health monitoring by analyzing faint random vibration cased by environmental noise. It has been confirmed that stable analysis results can be obtained through the experimental monitoring of the resonant frequency of an actual building. This report verifies the accuracy of the proposed diagnostic method by comparing the estimation result of the resonant frequency of the building by the proposed passive diagnosis with the active diagnostics result. As a result, it was confirmed that the proposed passive monitoring method can estimate the resonant frequency of the building with relative error of about one percent.