Importance of Implied Strength Correction for 1D Site Response at Shallow Sites at a Moderate to Low Seismicity Region

Aaqib, Muhammad; Sadiq, Shamsher; Park, Duhee; Hashash, Youssef M. A.; Pehlivan, Menzer

doi:10.1061/9780784481462.043

Cited by 10 publications

(12 citation statements)

References 6 publications

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“…The General Quadratic/Hyperbolic (GQ/H) model of Groholski et al (2016) implemented in DEEPSOIL v7 (Hashash et al, 2017) was used to apply the strength correction, which was reported to be important even for shallow deposits in regions of moderate to low seismicity (Aaqib et al, 2018). To define the shear strength for the GQ/H constitutive model, the Mohr-Coulomb model was used.…”

Section: Analysis Methodsmentioning

confidence: 99%

Simulation-based site amplification model for shallow bedrock sites in Korea

et al. 2021

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A new simulation-based site amplification model for shallow sites with thickness less than 30 m in Korea is developed. The site amplification model consists of linear and nonlinear components that are developed from one-dimensional linear and nonlinear site response analyses. A suite of measured shear wave velocity profiles is used to develop corresponding randomized profiles. A VS30 scaled linear amplification model and a model dependent on both VS30 and site period are developed. The proposed linear models compare well with the amplification equations developed for the western United States (WUS) at short periods but show a distinct curved bump between 0.1 and 0.5 s that corresponds to the range of site natural periods of shallow sites. The response at periods longer than 0.5 s is demonstrated to be lower than those of the WUS models. The functional form widely used in both WUS and central and eastern North America (CENA), for the nonlinear component of the site amplification model, is employed in this study. The slope of the proposed nonlinear component with respect to the input motion intensity is demonstrated to be higher than those of both the WUS and CENA models, particularly for soft sites with VS30 < 300 m/s and at periods shorter than 0.2 s. The nonlinear component deviates from the models for generic sites even at low ground motion intensities. The comparisons highlight the uniqueness of the amplification characteristics of shallow sites that a generic site amplification model is unable to capture.

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Section: Analysis Methodsmentioning

confidence: 99%

Simulation-based site amplification model for shallow bedrock sites in Korea

et al. 2021

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“…One-dimensional (1D) ground response analysis is commonly performed to evaluate the seismic hazard of the site-specific area [12][13][14][15]. Shylamoni et al [12] evaluated ground response at the Kashiwazaki-Kariwa Nuclear Power Plant site (Japan).…”

Section: Introductionmentioning

confidence: 99%

“…Satyam and Towhata [14] assessed the ground response and liquefaction of the Vijayawada city (India). Aaqib et al [15] Aaqib et al [16] investigated the strength correction effect of sites in Korea. Recently, several studies have examined seismic hazard assessment of the Hanoi region ground [2,7,17,18].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Seismic Site Amplification Using 1D Site Response Analyses at Ba Dinh Square Area, Vietnam

Tran

Aaqib

Nguyen

et al. 2021

Advances in Civil Engineering

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This study presents a case study on ground response analysis of one of the important cultural heritages in Hanoi, Vietnam. One-dimensional nonlinear and equivalent linear site response analyses which are commonly applied to solve the problem of seismic stress wave propagation are performed at the Ba Dinh square area. A measured in-situ shear wave velocity profile and corresponding geotechnical site investigation and laboratory test data are utilized to develop the site model for site-specific ground response analysis. A suite of earthquake records compatible with Vietnamese Design Code TCVN 9386: 2012 rock design spectrum is used as input ground motions at the bedrock. A few concerns associated with site-specific ground response evaluation are analyzed for both nonlinear and equivalent linear procedures, including shear strains, mobilized shear strength, and peak ground acceleration along with the depth. The results show that the mean maximum shear strains at any soil layer are less than 0.2% in the study area. A deamplification portion within the soil profile is observed at the layer interface with shear wave velocity reversal. The maximum peak ground acceleration (PGA) at the surface is about 0.2 g for equivalent linear analysis and 0.16 g for nonlinear analysis. The ground motions are amplified near the site natural period 0.72 s. The soil factors calculated in this study are 1.95 and 2.07 for nonlinear and equivalent linear analyses, respectively. These values are much different from the current value of 1.15 for site class C in TCVN 9386: 2012. A comparison of calculated response spectra and amplification factors with the local standard code of practice revealed significant discrepancies. It is demonstrated that the TCVN 9386: 2012 soil design spectrum is unable to capture the calculated site amplification in the study area.

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“…However, in many regions the most common and popular test is SPT. Shear wave velocity profile is developed using SPT-Vs correlations [5][6][7][8][9]. time average soil shear wave velocity (Vs, soil) and depth to bed rock (Dbed, rock) for the shallow bed rock sites [8,10].…”

Section: Introductionmentioning

confidence: 99%

GIS based Vs30, Vsz & Dbed rock Mapping for the Shallow Sites of Islamabad, Pakistan

Shahkar

Arshad

Sadiq

et al. 2021

Journal of Applied and Emerging Sciences

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The location of Pakistan is in a collision zone among the Eurasian and Indian plate boundaries. The geological framework of the Northwest Himalaya makes Northern Pakistan susceptible to frequent moderate to major earthquakes. The devastating earthquake of October 8, 2005 caused 87,000 deaths, 2.8 million displacements and financial loss of 200 Billion USD equivalent to 6% GDP of Pakistan. Islamabad is in seismically active region, the studies conducted for this region addresses the poor soil conditions, nonengineering construction practices and high level of seismic shaking. However, none of these studies provided readily available ground maps (top 30m time average shear wave velocity Vs30, average soil shear wave velocity Vsz & depth to bed rock Dbed rock) based on site specific geotechnical database. Vs30, Vsz & Dbed rock are important parameters for the evaluation of dynamic site characteristics of shallow bed rock sites. In Pakistan, Uniform Building Code (UBC-1997) is currently practiced, and the site classification are defined using site specific Vs30. In this study, geotechnical borehole database of 57 sites of Islamabad was collected to develop GIS based Vs30, Vsz & Dbed rock maps using Standard Penetration Test value (SPT-N). The borehole database includes, SPT-N, soil description and unit weight of soil for the Islamabad sites. In order to develop shear wave velocity (Vs) profiles, the available Vs-SPT empirical correlations were evaluated where both SPT-N & Vs measured data is available. The average of selected bounding correlations was applied to SPT-N database to develop representative Vs profiles. Using these Vs profiles, Vs30, Vsz & Dbed rock GIS based maps were developed by applying Kriging interpolation in open source QGIS software. The proposed GIS maps can be used in preliminary earthquake design for seismic resilient earthquake design in Islamabad, Pakistan.

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Importance of Implied Strength Correction for 1D Site Response at Shallow Sites at a Moderate to Low Seismicity Region

Cited by 10 publications

References 6 publications

Simulation-based site amplification model for shallow bedrock sites in Korea

Simulation-based site amplification model for shallow bedrock sites in Korea

Evaluation of Seismic Site Amplification Using 1D Site Response Analyses at Ba Dinh Square Area, Vietnam

GIS based Vs30, Vsz & Dbed rock Mapping for the Shallow Sites of Islamabad, Pakistan

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