Response study of a 51-story-tall Los Angeles, California building inferred from motions of the Mw7.1 July 5, 2019 Ridgecrest, California earthquake

Mehmet Celebi; Dan Swensen; Hamid Haddadi

doi:10.1007/s10518-021-01053-9

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Response study of a 51-story-tall Los Angeles, California building inferred from motions of the Mw7.1 July 5, 2019 Ridgecrest, California earthquake

Mehmet Celebi·Dan Swensen·Hamid Haddadi

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Abstract

A 51-story building in downtown Los Angeles that is equipped with a seismic monitoring accelerometric array recorded the Mw7.1 Ridgecrest, California earthquake of July 5, 2019. The building is a dual-core reinforced-concrete shear-wall and perimeter-column structure with ~ 80% of floors constructed as post-tensioned flat slabs, which makes it a trending design. Using system identification methods, spectral analyses, and coherence-phase angle computations, the recorded response data allowed the identification of dynamic response characteristics (fundamental frequencies of [NS] 0.21 Hz, [EW] 0.28 Hz, and [Torsional] 0.45 Hz, critical damping percentages < 2.5%, and associated mode shapes), as well as computation of drift ratios with maximum peaks of 0.145% for both NS and EW directions. The critical damping percentages are consistent with those recommended by LATBSDC ( 2017 ). There is no indication from the records that post-tensioned slab design played any role in altering the dynamic characteristics.

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Source-reported bounding extent: 34.022786817002° to 34.07768740409027° latitude; -118.28189849853514° to -118.21495056152342° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Mehmet Celebi, Dan Swensen, Hamid Haddadi. 2021-02-19. Response study of a 51-story-tall Los Angeles, California building inferred from motions of the Mw7.1 July 5, 2019 Ridgecrest, California earthquake. https://doi.org/10.1007/s10518-021-01053-9

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