Engineering Characteristics and Damage Potential of Ground Motions Recorded in the 2019 Ridgecrest Earthquake Sequence
Session: Observations From the 2019 Ridgecrest Earthquake Sequence
Type: Oral
Date: 4/28/2020
Time: 04:45 PM
Room: 115
Description:
We present a database and analysis of ground motions recorded during three events that occurred as part of the July 2019 Ridgecrest Earthquake Sequence: a magnitude M6.4 foreshock on a left-lateral cross fault, a M5.4 foreshock on a right-lateral fault perhaps associated with the Little Lakes fault zone and the M7.1 mainshock, also occurring on the same fault. We collected and uniformly processed 1,408 three-component recordings from an array of 906 sensors spanning eleven seismographic networks. Novel procedures for assignment of site metadata were employed, leveraging multiple models for the time-averaged shear-wave velocity in the upper 30 m (VS30) and for basin depth terms. Ground motions were processed following standard NGA procedures and the corrected records were used to compute various intensity measures including spectral acceleration at a number of oscillator periods and both traditional linear elastic and inelastic response spectra. These elastic and inelastic response spectra were compared to seismic design prescribed in building codes to evaluate the damage potential of the ground motions at spatially distributed sites. Residuals of the observed spectral accelerations relative to NGA-West2 ground motion models (GMMs) show good agreement between observations and model predictions. The average attenuation with distance is well captured by the empirical NGA-West2 GMMs. An analysis considering directivity and fault slip heterogeneity for the M7.1 event demonstrates that the dispersion in the near-source (rupture distances < 40 km) ground motion residuals can be reduced by as much as 30%.
Presenting Author: Sean K. Ahdi
Authors
Sean K Ahdi sahdi@ucla.edu Exponent, Inc., University of California, Los Angeles, Los Angeles, California, United States Presenting Author
Corresponding Author
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Silvia Mazzoni smazzoni@ucla.edu University of California, Los Angeles, Los Angeles, California, United States |
Tadahiro Kishida tadahiro.kishida@ku.ac.ae Khalifa University, University of California, Los Angeles, Abu Dhabi, , United Arab Emirates |
Pengfei Wang wltcwpf@g.ucla.edu University of California, Los Angeles, Los Angeles, California, United States |
Chukwuebuka C Nweke ebuka@ucla.edu University of California, Los Angeles, Los Angeles, California, United States |
Nicolas M Kuehn kuehn@g.ucla.edu University of California, Los Angeles, Los Angeles, California, United States |
Victor Contreras vcontreras@ucla.edu University of California, Los Angeles, Los Angeles, California, United States |
Badie Rowshandel browshandel@calquake.com California Earthquake Authority, Sacramento, California, United States |
Jonathan P Stewart jstewart@seas.ucla.edu University of California, Los Angeles, Los Angeles, California, United States |
Yousef Bozorgnia Yousef.Bozorgnia@ucla.edu University of California, Los Angeles, Los Angeles, California, United States |
Engineering Characteristics and Damage Potential of Ground Motions Recorded in the 2019 Ridgecrest Earthquake Sequence
Category
Observations From the 2019 Ridgecrest Earthquake Sequence