Empirical filtering method for natural frequencies evaluation of low rise reinforced concrete school building using ambient vibration approach

Ambient vibrations composed by various sources of seismic noise wave field from nature and human activities captured, may perturb the origin natural frequency of an investigated structure without careful data processing conducted' A simple empirical filtering protocol has been introduced with application of Fourrier Amplitude Spectra (FAS) and Horizontal to Vertical Spectral Ratio (HVSR) methods' in order to determine the predominant frequencies of a 4-storey reinforced concrete primary school building in Johor Malaysia. Three predominant modes of building frequencies at 4.21 Hz and 6.58 Hz in transverse axis and 4.35 Hz in the longitudinal axis significantly observed in computed spectral and successfully agreed to the verification filtering protocol introduced, with relative deviation lesser than 7.13%.