SEISMIC PERFORMANCE ASSESSMENT OF A TALL BUILDING HAVING PRE-NORTHRIDGE MOMENT-RESISTING CONNECTIONS

摘要

The Pacific Earthquake Engineering Research (PEER) Center has expanded its Tall Building Initiative project to include assessment of the seismic performance of existing tall steel buildings. Thus far, buildings investigated were 20 stories or more in height, and constructed between the 1960 and 1990. During this period, many tall buildings were constructed in California, but earthquake-resistant design procedures were not fully developed. The number of buildings fitting these criteria in San Francisco, California alone is on the order of 80. From these structures, a 35-story steel building, designed in 1968, and having representative details from that period, was selected for evaluation. In this paper, results from one of four three-dimensional nonlinear analysis models developed to assess the potential seismic performance of this structure are presented. Two earthquake hazard levels based on ASCE 41 recommendations are used for the evaluation. Structural responses are computed using state-of-the-art analysis tools. The structural analysis results are interpreted to assess the impact of suspected deficiencies on seismic response, and the ability of different evaluation guidelines, numerical models and analysis methods to identify seismic vulnerabilities. With this understanding, retrofit strategies can be assessed.