On-Site Nonlinear Hysteresis Curves and Dynamic Soil Properties

Ghayamghamian, Mohammad Reza; Kawakami, Hideji

doi:10.1061/(asce)1090-0241(2000)126:6(543)

Cited by 20 publications

(9 citation statements)

References 8 publications

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“…These findings were consistent with the outcome of similar identifications conducted using experimental data of centrifuge models of level sites and infinite slopes [27,108]. Ghayamghamian and Kawakami [38], and Taboada U. et al [91] applied this technique to analyze earthquake acceleration records of downhole array sites in Japan, and Mexico, respectively. In a recent publication, Zeghal and Abdel-Ghaffar [103] applied the same approach to obtain approximate shear stress-strain estimates of Long Valley earth dam.…”

Section: Stress-strain Imagingsupporting

confidence: 84%

A survey of geotechnical system identification techniques

Oskay

Zeghal

2011

Soil Dynamics and Earthquake Engineering

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Identification and inverse problem techniques play an important role in the characterization and modeling of geotechnical systems. These techniques have been used in estimation of system parameters, model development and calibration, as well as simulation of earthquake ground motions. The recent availability of high quality seismic records of sites equipped with downhole accelerometer arrays led to a burgeoning of identification and inverse problem studies involving geotechnical systems. This paper presents a survey of system identification techniques and analyses of full-and small-scale soil systems, with an emphasis on geotechnical earthquake engineering problems.

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Section: Stress-strain Imagingsupporting

confidence: 84%

A survey of geotechnical system identification techniques

Oskay

Zeghal

2011

Soil Dynamics and Earthquake Engineering

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“…Furthermore, the author also analysed the nonlinear soil response using stress-strain relationship in the time domain. The results of time domain analysis validate those obtained by segmental cross-spectrum at the sites [Ghayamghamian and Kawakami, 2000]. Thus, the degree of nonlinearity seems to be reasonably evaluated by segmental crossspectrum in compare with Fourier spectrum.…”

Section: Nonlinear Soil Response and Segmental Cross-spectrumsupporting

confidence: 76%

“…strain level). Ghayamghamian and Kawakami [2000] analysed dynamic soil properties in the time domain using direct estimation of stress-strain hysteresis curves for the same time windows at the sites [Ghayamghamian and Kawakami, 2000]. Since the level of excitation is significantly different between time windows of large and small events at the sites, the soil properties for the average of strain level at each time window is determined and employed in 1D model for calculation of theoretical amplification function.…”

Section: Application Of Segmental Cross-spectrum To Actual Earthquakementioning

confidence: 99%

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Ghayamghamian¹

2005

J. Earth. Eng.

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Different aspects of spectral analysis for site response evaluation are investigated in this study. The segmental cross-spectrum is proposed in spectral analysis of earthquake ground motions. The performance of segmental cross-spectrum in contrast with the conventional methods is investigated through the mathematical modelling, numerical analysis and application to earthquake data recorded at Chiba and Shinfuji downhole arrays in Japan. In analysis of earthquake data, the soil amplification function is identified using both uphole/downhole (U/D) and H/V spectral ratios. The advantage of segmental cross-spectrum is assessed by comparing identified amplification functions using different spectral methods and theoretical soil response. The reliability of site response estimations obtained by H/V spectral ratio using segmental cross-and Fourier spectra is also examined by means of cross-validation with the U/D spectral ratio of earthquake motion and theoretical soil response. Furthermore, the application of segmental crossspectrum in nonlinear soil response is examined by comparing the amplification function of weak and strong motions for both methods. The results validate the advantage of segmental cross-spectrum in both linear and nonlinear soil response, particularly, when it used with H/V technique.

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“…Koga and Matsuo (1990) developed shear stress-strain hysteresis loops using accelerometer data embedded in a reduced scale embankment rested on liquefiable soil and tested on 1-g shaking table. Similar concepts have been used by Abdel-Gaffar and Scott (1979), Kikusawa and Hasegawa (1985), and Ghayamghamian and Kawakami, (2000) to determine shear modulus and damping from measured responses of real earth structures during earthquakes. One-dimensional shear beam idealization proposed by Zeghal et al (1995) have been used to quantify the dynamic properties of soil from small-scale dynamic centrifuge tests (Bernnan et al 2005, Elgamal et al 2005.…”

Section: Nonlinear Hysteresis and Dynamic Soil Propertiesmentioning

confidence: 92%

Modulus and damping from shaking table tests of reinforced soil walls

El-Emam

2014

Geomechanics and Geoengineering

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The paper presents rational procedures to estimate normalised shear modulus and damping ratio from measured responses of reinforced soil model walls tested in a 1-g shaking table. Displacement measured at the top of the model walls and input base acceleration time histories are used to produce equivalent hysteretic responses of the model walls. Equivalent hysteretic loops at different strain amplitudes are developed and used to calculate normalised modulus degradation curves and damping ratio for the tested model walls. Model wall responses are also analysed using the single degree of freedom (SDOF) model to determine damping ratio and phase difference, and to verify the validity of SDOF model for application with reinforced soil walls.Results indicate that the normalised shear modulus significantly decreased at the early stage of the base shaking (i.e. γ s < 0.03%). For example, about 68% and 80% reductions in shear modulus occurred at γ s = 0.005% and 0.01% respectively. In addition, a 90% reduction in the normalised shear modulus realised at relatively strong input base acceleration (i.e. for γ s > 0.03%). Minimum damping ratio of 5% to 10% for both model walls was obtained, increased to 15% to 20% at strain amplitude γ s = 0.3%, and reached higher values thereafter. Finally, dynamic properties determined from the proposed method are compared with experimental and empirical relationships proposed in literature as well as resonant column test results.

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On-Site Nonlinear Hysteresis Curves and Dynamic Soil Properties

Cited by 20 publications

References 8 publications

A survey of geotechnical system identification techniques

A survey of geotechnical system identification techniques

Untitled

Modulus and damping from shaking table tests of reinforced soil walls

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