000019924 001__ 19924
000019924 005__ 20170118182346.0
000019924 04107 $$aeng
000019924 046__ $$k2017-01-09
000019924 100__ $$aDeierlein, Gregory
000019924 24500 $$aPhysical Mechanisms Underlying the Influence of Ground Motion Duration on Structural Collapse Capacity

000019924 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000019924 260__ $$b
000019924 506__ $$arestricted
000019924 520__ $$2eng$$aThis study explores the physical mechanisms by which the duration of strong ground motion influences structural response. While a number of previous studies have found that ground motion duration influences only cumulative damage indices, and not peak structural deformations, a few recent studies that employed realistic, deteriorating structural models were able to demonstrate the effect of duration on peak deformations and structural collapse capacity. These recent studies were, however, empirical in nature and did not fully explore the reasons behind the observed effects of duration. Many of the previous studies qualitatively attributed the effects to the cyclic deterioration of strength and stiffness of the structural components, which represents just one mechanism by which duration exerts its influence. In contrast, the present study shows that the gradual ratcheting of drifts, accentuated by the destabilizing P − ∆ effect, is an equally important mechanism by which duration influences structural response. The relative contributions of the two mechanisms—cyclic deterioration and ratcheting—to the observed influence of duration on the collapse capacity of a five-story steel moment frame building, are quantified by conducting incremental dynamic analysis (IDA) using spectrally equivalent sets of long and short duration ground motions. The use of spectrally equivalent ground motions allows controlling for the effect of response spectral shape. A response parameter called the ratcheting interval is defined and used to explain the larger potential for a long duration ground motion to cause structural collapse, when compared to a spectrally equivalent short duration ground motion scaled to the same intensity level. These findings shed light on the interaction between structural model characteristics and the observed influence of ground motion duration on structural response. In addition, they highlight the importance of using models that capture both cyclic deterioration and the P − ∆ effect to reliably account for the effect of ground motion duration when assessing structural collapse risk.

000019924 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000019924 653__ $$aground motion duration; cyclic deterioration; ratcheting; collapse capacity; nonlinear dynamic analysis

000019924 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000019924 720__ $$aDeierlein, Gregory$$iBaker, Jack$$iChandramohan, Reagan
000019924 8560_ $$ffischerc@itam.cas.cz
000019924 8564_ $$s972112$$uhttps://invenio.itam.cas.cz/record/19924/files/470.pdf$$yOriginal version of the author's contribution as presented on USB, paper 470.
000019924 962__ $$r16048
000019924 980__ $$aPAPER