Dávalos, Héctor
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Dávalos, Héctor
Official Name
Dávalos Alejo, Héctor Gabriel
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ORCID
Scopus Author ID
57204065130
Researcher ID
S-2043-2018

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Directionality of FIV3 ground-motion intensities during the 6 February 2023 Kahramanmaraş, Türkiye earthquake doublet

2024 , Miguel Bravo-Haro , Pablo Heresi , Dávalos, Héctor , Eduardo Miranda

At present time, ground-motion prediction models neglect the directionality observed in horizontal components of earthquake ground motions, that is, the important changes in ground-motion intensity that occur with changes in azimuth. This study presents an investigation of the directionality of a recently proposed measure of ground-motion intensity during the 6 February 2023, Mw 7.8 Pazarcık and Mw 7.5 Elbistan earthquake doublet in the Kahramanmaraş region of Türkiye, which resulted in the collapse of more than 35,000 buildings and caused almost 60,000 fatalities. The studied intensity measure is referred to as FIV3, which has been shown to be better correlated with structural collapse than the spectral acceleration at the fundamental period of the structure. The improved intensity measure is period-dependent and is computed as the sum of the three largest incremental velocities with the same polarity obtained from the area under segments of a low-pass filtered ground acceleration time series. The following aspects are studied in this article: variation of FIV3 intensity with changes in the orientation; variation of FIV3 intensity with changes in the period of vibration; attenuation of FIV3 intensities with increasing distance; and spatial distribution of the orientation of maximum FIV3 intensity. This study is based on 231 pairs of records from the Mw 7.8 main event and 222 pairs of records from the Mw 7.5 event. Similarly to the directionality of spectral ordinates, it is found that the directionality of FIV3 intensity also increases with increasing period. Strong directionality occurred not only in the near field but up to distances as large as 400 km from the epicenter. The orientation of maximum FIV3 intensity is found to occur close to the transverse orientation, consistent with observations for the orientation of maximum spectral ordinates during strike-slip earthquakes.

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Filtered incremental velocity: A novel approach in intensity measures for seismic collapse estimation

2019 , Dávalos, Héctor , Eduardo Miranda

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Overview of collapsed buildings in Mexico City after the 19 September 2017 (Mw7.1) earthquake

2020 , Francisco A. Galvis , Eduardo Miranda , Pablo Heresi , Dávalos, Héctor , Jorge Ruiz-García

An intraslab normal-faulting earthquake struck the central region of Mexico on 19 September 2017, leading to the collapse of 44 buildings in Mexico City. After the earthquake, the authors collected information in situ and through social media about the collapsed buildings, which was statistically processed to identify the causes of their collapse. This article presents the main collapse statistics, which revealed that 64% of the collapsed buildings had between 1 and 5 stories, 61% had a seismic-force-resisting system based on reinforced concrete columns with flat slabs, 57% experienced a soft-story mechanism, 91% were built before 1985, 43% were located at the corner blocks, and 10% exhibited pounding with neighboring buildings. The spatial distribution of the collapsed buildings and the recorded ground motion features suggest that short- and medium-period buildings having well-known vulnerabilities were particularly prone to collapse under amplified high-frequency seismic waves typical of intraslab normal-faulting earthquakes, such as the 2017 Puebla–Morelos earthquake.

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Response spectral damping modification factors for structures built on soft soils

2022 , Dávalos, Héctor , Eduardo Miranda , James Bantis , Cristian Cruz

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Evaluation of the Scaling Factor Bias Influence on the Probability of Collapse Using Sa(T1) as the Intensity Measure

2019 , Dávalos, Héctor , Eduardo Miranda

Amplitude scaling is a common approach to modify recorded ground motions to achieve a desired intensity level. The possible bias introduced by scaling the amplitude of ground motions when using the first-mode spectral ordinate as the intensity measure is evaluated using intensity-based analyses. This study evaluates whether upward scaling introduces bias in lateral displacement demands, but more importantly, in the probability of collapse. The latter, which is of utmost importance, has received little attention in previous studies. Analyses were conducted using degrading single-degree-of-freedom and multiple-degree-offreedom systems with different fundamental periods of vibration and normalized strengths subjected to different sets of recorded accelerograms requiring different scale factors to reach a target intensity. The results demonstrate that this type of amplitude scaling introduces a bias in which lateral displacement demands and collapse estimates are increasingly overestimated with an increasing scale factor and that the bias is strongly dependent on the period and lateral strength of the system. Furthermore, the bias is considerably larger in collapse risk estimates.

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Evaluation of FIV3 as an Intensity Measure for Collapse Estimation of Moment-Resisting Frame Buildings

2020 , Dávalos, Héctor , Eduardo Miranda

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A Ground Motion Prediction Model for Average Spectral Acceleration

2018 , Dávalos, Héctor , Eduardo Miranda

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Robustness evaluation of fiv3 using near-fault pulse-like ground motions

2021 , Dávalos, Héctor , Eduardo Miranda

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A ground motion prediction equation for filtered incremental velocity, FIV3

2020 , Dávalos, Héctor , Pablo Heresi , Eduardo Miranda

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Directionality of average spectral acceleration, SaAvg, in the 2023 Kahramanmaras, Türkiye earthquake sequence

2024 , Maria Liapopoulou , Dávalos, Héctor , Miguel Bravo-Haro , Pablo Heresi , Eduardo Miranda

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