EVALUATION OF THE SEISMIC RESPONSE OF BUILDINGS OBTAINED THROUGH ANALYTICAL AND EXPERIMENTAL PROCEDURES

摘要

To asses the quality of the current models and analysis procedures a comparison of experimental results, using the records obtained in a typical shear wall reinforced concrete building in downtown Santiago, with corresponding results obtained using conventional methods of modeling and analysis is made. A study of the response in the time domain (absolute accelerations measured at different floor levels and locations) provides insight of the overall behavior of the building. The identification of the fundamental vibration frequencies of the structure is based on the study of the Fourier amplitudes of the measured accelerations. In addition, empirical transfer functions are computed as the ratio between the acceleration values measured in the upper floors and the values measured at the base and they are compared to the corresponding analytical transfer functions. Finally, the properties that control the dynamic response are obtained using standard system identification procedures on the measured signals. The comparison of the analytical and the experimental results shows significant differences in the vibration frequencies of the lower modes (up to 30%). The damping ratios are found to be of the order of 2%. A correlation analysis of the measured response shows that the transverse direction has a coupling with the rotation that is mildly superior to the coupling between the longitudinal direction and the rotation. This is not reflected by the analytical model that shows larger coupling between the longitudinal translations and the rotation.