Available at: https://digitalcommons.calpoly.edu/theses/687
Date of Award
MS in Architecture - Architectural Engineering
The determination of a building’s modal parameters (natural periods and mode shapes) using ultra-low level forced vibration testing and analytical modeling were critically compared. The structure utilized for this experiment is the Robert E. Kennedy Library on the campus of California Polytechnic State University San Luis Obispo, a five-story reinforced concrete shear wall structure. The specific testing procedure used has been verified to produce accurate results in smaller buildings, but the Kennedy Library represents the most massive subject structure. Other characteristics of this structure that make it unique include a large atrium at the center of the building and modes that are closely spaced in the frequency domain. Comparing the results from the computational models and the experimental analysis showed that the computational models underestimated the building periods by approximately 6-12%. This discrepancy in the results was attributed to an underestimation of the building mass, possible soil-structure interaction, and likely cracking of the concrete slab and shear walls. Modeling of the shear walls as both line elements and area elements was also explored and the consequences of each were determined.