COMPARISION OF DIFERENT SIMPLIFIED METHODS FOR SEISMIC ASSESMENT OF CONCENTRIC BRACED FRAMES

Besides the complex instructions of guidance documents for seismic rehabilitation of existing buildings, some institutions have provided simple criteria in terms of simplified rehabilitations.ASCE 41-06 is one of documents that introduced a simple method for assessment of certain buildings that do not require advanced analytical procedures. Furthermore the New Zealand guideline has presented a simple lateral mechanism analysis that is a hand static analysis for determining the probable collapse mechanism, lateral strength and displacement capacity of the structure. In this study the accuracy of simplified methods is examined on samples of steel concentric braced frames. Next the PGA values that cause their collapse are determined and these results are compared with the corresponding values determined by Incremental Dynamic Analysis. After comparison of obtained results, suggestions are presented to improve seismic retrofit criteria.

Keywords:

Pushover Analysis , Nonlinear Dynamic Analysis , Moment Frames , Braced Frames , Peak Ground Acceleration Failure (PGAf)