Evaluation Of The Time-variant Characteristics Of Instrumented Structures Based On Strong Motion Records

Sheraton-Universal Hotel located in the North Hollywood of Los Angeles, California, USA is a twenty-story building consisting of ductile moment-resistant reinforced concrete frame structure system. Total 16 time histories of acceleration are recorded during the 1994 Northridge earthquake, California. Based on these recorded strong motions, the dynamic properties of the structure are estimated and the seismic performance of the hotel structure is evaluated in this dissertation. The main studies are following:1. The Sheraton-Universal Hotel is selected for case study, and the structure scheme, site condition, and strong motion recorded from the Northridge earthquake are collected.2. The data of the strong motions are analyzed and explained preliminarily.3. The time-variant modal parameters of the structure are recognized.4. The time-variant physical parameters of the structure are recognized.5. The finite element model is built based on the recognized physical parameters. The calculated results are proved to be reasonable by comparing with the actual strong motion records.6. The time-variant regulations of the stiffness between stories of the structure could be obtained based on the recognized mode parameters by means of the interpolation method.7. The torsional response of the structure and influence of higher mode shape are evaluated. The time-variant torsional stiffnesses of the structure are recognized.