Empirical frequency content models based on intermediate-depth earthquake ground-motions

Yaghmaei‐Sabegh, Saman; Pavel, Florin; Shahvar, Mohammad P.; Qadri, S. M. Talha

doi:10.1016/j.soildyn.2022.107173

Cited by 9 publications

(5 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A ground motion database of recordings from five Vrancea intermediate-depth earthquakes having moment magnitudes M W ≥ 6.0 is compiled for this analysis. The database is a part of the larger ground motion database used in the past studies of Yaghmaei-Sabegh et al [32] and Pavel and Yaghmaei-Sabegh [33], which deal with the evaluation of the mean period T M and of the control period T C for intermediate-depth earthquakes. Only ground motion recordings having a minimum peak ground acceleration (PGA) of 0.05 g [34] are selected for the analysis.…”

Section: Evaluation Of the Number Of Equivalent Cyclesmentioning

confidence: 99%

Assessment of Liquefaction Hazard for Sites in Romania Using Empirical Models

Pavel,

Vladut

2023

Infrastructures

Self Cite

View full text Add to dashboard Cite

This paper is focused on the evaluation of the liquefaction hazard for different sites in Romania. To this aim, a database of 139 ground motions recorded during Vrancea intermediate-depth earthquakes having moment magnitudes MW ≥ 6.0 is employed for the evaluation of the equivalent number of cycles for this seismic source. Several functional forms for the empirical evaluation of the equivalent number of cycles considering various seismological or engineering parameters are tested and evaluated. The regression analysis shows smaller uncertainties for the empirical models based on ground motion engineering parameters. Considering the lack of information in terms of engineering parameters, a simpler empirical model which accounts for the earthquake magnitude, source–site distance and soil conditions is selected for the liquefaction hazard analysis. Based on the proposed empirical model, specific magnitude scaling factors for Vrancea intermediate-depth earthquakes are proposed for the first time as well. The liquefaction hazard analysis is performed for sites whose seismic hazard is generated by either the Vrancea intermediate-depth seismic source or by local shallow crustal seismic sources. In the case of some of the selected sites, liquefaction phenomena were observed during past large-magnitude earthquakes. Unlike previous studies dealing with liquefaction analyses for sites in Romania, in this research, the hazard assessment is performed for various ground motion levels evaluated based on probabilistic seismic hazard assessment. Liquefaction hazard curves are constructed for each analyzed site. The results of the liquefaction hazard analysis show that this phenomenon is more likely to occur in the areas exposed to Vrancea intermediate-depth earthquakes, compared to the areas affected by local shallow earthquakes. In the case of the analyzed soil profiles from Bucharest, Craiova and Ianca, the minimum liquefaction safety factors less than one even for seismic hazard levels having mean return periods of 100 years and less.

show abstract

Section: Evaluation Of the Number Of Equivalent Cyclesmentioning

confidence: 99%

Assessment of Liquefaction Hazard for Sites in Romania Using Empirical Models

Pavel,

Vladut

2023

Infrastructures

Self Cite

View full text Add to dashboard Cite

show abstract

“…This database was also used recently in a study by Yaghmaei-Sadegh et al [30] dealing with empirical models for the mean period T M of ground motions recorded during intermediate-depth earthquakes. The database consists of a total of 196 ground motions recorded during the five intermediate-depth earthquakes mentioned previously.…”

Section: Ground Motion Databasementioning

confidence: 99%

“…As such, the model is developed using only data from moderate and large Vrancea earthquakes with moment magnitudes of M W ≥ 6.0. In the case of this seismic source, it has to be emphasized that empirical models have been proposed for spectral accelerations [24][25][26], spectral displacements [27], macroseismic intensities [28,29], or mean periods [30]. An analysis of the possible geographical patterns related to the distribution of ground motion durations during intermediate-depth earthquakes with the largest number of available recordings is performed as well.…”

Section: Introductionmentioning

confidence: 99%

Ground Motion Duration Patterns for Vrancea (Romania) Intermediate-Depth Earthquakes

Pavel,

Nica

2023

Geosciences

Self Cite

View full text Add to dashboard Cite

This study is focused on evaluating ground motion durations of Vrancea intermediate-depth earthquakes in Romania, in the context of future updates to the Romanian seismic design code P100-1/2013. The ground motion database compiled for this study consists of about 200 ground motions recorded during five moderate and large Vrancea intermediate-depth earthquakes that occurred in the period of 1977–2004 and had moment magnitudes of MW ≥ 6.0. Two empirical models were derived in this study for the significant ground motion duration considering two time intervals (5–75% and 5–95%) for the accumulation of the Arias Intensity IA. An analysis of the data shows that the mean ratio between D5-95 and D5-75 is about 2.8. Moreover, the regression also shows that the largest share of variability is due to the within-event component (site term). Among the regression coefficients, the hypocentral distance and the soil conditions appear to have a larger impact on the ground motion duration compared to the earthquake magnitude. It was also observed that the median ground motion durations predicted using the empirical model proposed in this study were much smaller than the ones from the proposed Eurocode 8 draft for the same magnitude range. Finally, geographic trends related to the distribution of residuals were also evaluated using the data from the three earthquakes with the largest number of available ground motion recordings.

show abstract

“…Knowing the seismic vulnerability of the country, the next expectation was to design the surface ground motion maps of Pakistan from the tehsil to city level. Most of Pakistan's published seismic hazard assessment studies cover the regional extent [7][8][9][10][11][12][13]. Unfortunately, only a few microzonation studies have been completed [4,[14][15][16][17][18][19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Application of Probabilistic Seismic Hazard Assessment to Understand the Earthquake Hazard in Attock City, Pakistan: A Step towards Linking Hazards and Sustainability

et al. 2023

View full text Add to dashboard Cite

Within the last three decades, twelve major earthquakes (Mw > 6.0) have jolted Pakistan and contributed to a heavy death toll and an economic loss of billions of dollars, which is immense for any underdeveloped country. Despite the generalized description of seismic hazards in various regions of Pakistan, densely populated cities still require a detailed and integrated vulnerability analysis to overcome the impact of a significant earthquake. This study aims to integrate seismic hazard assessment schemes to understand the vulnerability of Attock city against an earthquake. It initially evaluates the threat from an earthquake due to tectonic activity in the region, splits the region (about 200 km radius) into six seismic zones and uses area source parameters. The ground motion prediction equations compatible with the study area’s seismotectonic environment are also used in this study. Peak horizontal ground acceleration (PGA) and 5% damped spectral acceleration are critical features of ground motions. The site classification is carried within Attock city, indicating the presence of SB (foundation condition with Vs30 = 760 m/s), SC (foundation condition with Vs30 = 400 m/s) and SD (foundation condition with Vs30 = 300 m/s). The peak ground accelerations for a return period of 475 years at the SB, SC and SD sites are estimated as 0.23 g, 0.28 g and 0.30 g, respectively. Uniform hazard spectra are obtained for each site classification at three return periods (475, 975 and 2475 years). Another possible threat can be the local site conditions of the study area, as Attock city exists on the unlithified sediments of upper Pleistocene to Recent alluvial deposits. That is why microtremor recordings are conducted at 20 sites within Attock city to understand the fundamental frequency (f0), horizontal to vertical spectral amplitude (A0) and Kg parameter, a seismic vulnerability index. The values of f0 are found between 0.6 and 9 Hz and A0 is observed between 2.1 and 5 Hz, whereas the Kg is estimated between 0.24 and 20 Hz. Despite evidence of the seismic vulnerability of Attock city, the current building designs and infrastructure development are not synchronized with the uniform hazard response spectra and the soil amplification, thus enhancing the exposure of the study area to disaster during a major earthquake. This study will be instrumental in pre-disaster mitigation strategies for urban planners and policymakers.

show abstract

Empirical frequency content models based on intermediate-depth earthquake ground-motions

Cited by 9 publications

References 31 publications

Assessment of Liquefaction Hazard for Sites in Romania Using Empirical Models

Assessment of Liquefaction Hazard for Sites in Romania Using Empirical Models

Ground Motion Duration Patterns for Vrancea (Romania) Intermediate-Depth Earthquakes

Application of Probabilistic Seismic Hazard Assessment to Understand the Earthquake Hazard in Attock City, Pakistan: A Step towards Linking Hazards and Sustainability

Contact Info

Product

Resources

About