Application of Internally Damped Shearbeam Model to Analysis of Buildings under Earthquakes: Robust Procedure for Quick Evaluation of Seismic Performance

A step-by-step procedure for linear analysis of building structures with rigid floor beams is developed and presented. The method outputs the maximum story drift envelope, and consists of a series of explicit formulas that do not require iteration. The basis of the method is an internally damped shearbeam model. Drift demand spectra are used to provide information on the ground motion hazard of the site. In addition to the drift demand spectra, two additional spectra are incorporated, which describe the higher mode behavior. To test accuracy, three sample buildings structures (3-, 9-, and 20-story buildings at Los Angeles) are analyzed for five sample earthquake records using the proposed procedure, and conventional time history analysis. A comparison of the results shows that the proposed procedure is accurate enough for quick evaluation of seismic performance.