Determination to the period of a school building before and after its retrofitting using ambient vibration records

Abstract

Determining the dynamic parameters of the structures allows us to obtain a substantial amount of information about the state of the building. Recently, the determination of these parameters were performed through Structural Health Monitoring Systems (SHMSs), which are non-destructive methods. In scope of this study, the period values prior to and following the retrofitting of a school building, which are among the dynamic parameters, were examined. The Operational Modal Analysis (OMA) method, which is based on the principle of measuring the responses of ambient effects in the structure in the experimental study, has been utilized. For this purpose, response records taken from the building under the effect of ambient vibration were used. Before and after retrofitting, the records of the building under the effect of ambient vibration were taken from the same locations. 3 sensors were used to record ambient vibrations. The data from these sensors were transferred to a computer by using a data logger. In order to measure and evaluate the responses Enhanced Frequency Domain Decomposition Method (EFDDM) in the frequency domain and Stochastic Subspace Identification Method (SSIM) in the time domain were used. Following the analysis, a comparison of how the period values had changed was conducted.