Damage spectra of the mainshock-aftershock ground motions at soft soil sites. Issue 115 (December 2018)

• Record Type: Journal Article
• Authors: Wen, Weiping; Ji, Duofa; Zhai, Changhai; Li, Xiulin; Sun, Pengyu
• Is Part Of: Soil dynamics and earthquake engineering. Issue 115(2018)
• Page Start: 815
• Page End: 825
• Publication Date: 2018-12
• Subjects: Damage spectra -- Mainshock-aftershock (MSAS) sequence -- Soft soil -- Period normalization; Soil dynamics -- Periodicals; Earthquake engineering -- Periodicals; Sols -- Dynamique -- Périodiques; Génie parasismique -- Périodiques; 624.176205
• DOI: 10.1016/j.soildyn.2018.08.016
• Languages: English
• ISSNs: 0267-7261

Abstract

Abstract: The soft soil tends to amplify the damage accumulation induced by mainshock-aftershock (MSAS) sequences due to the significant amplification effect of soft soil on the ground motions. This manuscript proposes the damage spectra of MSAS ground motions at soft soil sites to quantify the accumulated damage experienced by the structures under the MSAS sequences. Artificial MSAS ground motions are firstly generated by the revised randomization method (i.e. combing two random records which belong to two different ground motion groups respectively). The effects of period normalization (i.e. the vibration period is normalized by the predominant period of mainshock ground motion) are discussed from the point of view of dispersion and mean. The effects of the aftershock ground motions at soft soil sites on the damage spectra are quantitatively studied. The results indicate that the period normalization can reduce the dispersion of damage spectra of MSAS sequences, but larger intensity of aftershock ground motion can contaminate the efficiency of period normalization. The effects of strong aftershocks at soft soil sites on the damage spectra can exceed 40%. Strong aftershock ground motions at soft soil sites tend to cause larger additional damage than those at firm soil sites. The prediction equations are finally proposed to predict the mean of damage spectra for MSAS sequences at soft soil sites. Highlights: Damage spectra are proposed for MSAS sequences at soft soil sites. Period normalization can reduce the dispersion of damage spectra of MSAS sequences. Larger intensity of aftershock can contaminate the efficiency of period normalization. The effects of strong aftershocks on the damage spectra of soft soil can exceed 40%. Prediction equation is proposed for the mean of damage spectra.