Strong motion characteristics of the 2022 Luding Ms6.8 earthquake,Sichuan province
At 12:52 Beijing time on September 5,2022,an Ms6.8 magnitude earthquake struck Luding County,Garze Prefecture,Sichuan Province.133 sets of three-component acceleration records were obtained by the National strong motion network.After preliminary screening and filtering of the records,the attenuation relationship between PGA and PGV,vertical ground motion characteristics and ground motion velocity pulses were studied,and the response spectrum and design spectrum were compared and analyzed,focusing on the correlation between earthquake damage and ground motion near the 051SMW station.The conclusions are as follows:1)PGA and PGV fitting curves of the strong motion records are similar for three kinds of stations,and the fitting curves of PGA and PGV are close to Huo Junrong's prediction model;2)The vertical ground motion is considerably significant,with approximately 38.2%of the strong motion records displaying a V/H ratio greater than 2/3.This factor could potentially contribute to the occurrence of seismic damage phenomena,including roof collapse,column torsion,and ceiling fall;3)11 records with velocity pulse characteristics were identified,which had a great influence on the long-period structure;4)Most of the selected recorded response spectra exceeded the horizontal section of the design spectrum of rare earthquakes,and the houses around the 051SMW station with velocity pulse characteristics were seriously damaged and the casualties were heavy.
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