Evaluation of current seismic design equations for nonstructural components in tall buildings using strong motion records

摘要

A recently completed California Strong Motion Instrumentation Program (CSMIP) data interpretationnproject used recorded ground and floor motion data to evaluate a key ASCE/SEI 7-05 (and 7-10) equationnfor seismic design of acceleration-sensitive building nonstructural components. CSMIP motions from 73nearthquakes recorded in 151 fixed-base buildings were used in the evaluation. An improved equation wasndeveloped with two categories of revisions. First, the current code formula considers a linear relationshipnbetween the peak floor acceleration (PFA) and the relative height of the component in the building with anroof PFA that is three times that of the peak ground acceleration. The analyses of the recorded motionsnshowed that improved results could be obtained by using a nonlinear relationship and by considering bothnthe building approximate period, Ta, and the level of ground motion. Second, the code formula considers ancomponent amplification factor, ap, that takes values between 1.0 and 2.5 depending on the flexibility of thennonstructural component. Analyses showed that component amplification factor can be better representednusing a three-segment spectrum composed of a linear rise from 1.0 to maximum value of ap at short periods,na flat segment with the maximum value of ap at medium-range periods and a nonlinear decaying segment atnlonger periods. The shape and amplitude of the spectrum were found to vary depending on Ta. This papernevaluates tall buildings with at least 15 stories using the proposed equations and confirms that the revisionsnprovide improvements in matching design equations with recorded response. Copyright © 2011 John Wileyn& Sons, Ltd.