Shear wave velocity measurements and soil–pile system identifications in dynamic centrifuge tests

Lee, Chung Jung; Hung, Wen Yi; Tsai, Chen Hui; Chen, Ting; Tu, Yichun; Huang, Chin‐Cheng

doi:10.1007/s10518-013-9545-1

Cited by 19 publications

(7 citation statements)

References 9 publications

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“…BE tests were conducted to provide information on the shear (G) and Young's (E) moduli. From the S-wave velocity (υS), the small strain shear modulus (Gmax), was determined, using the elastic wave velocity according to the equation [43,44]:…”

Section: Frequency Dependencymentioning

confidence: 99%

Dynamic Characterization of Cohesive Material Based on Wave Velocity Measurements

et al. 2016

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Abstract:The paper presents a description of the dynamic properties of cohesive material, namely silty clays, obtained by using one of the applied seismology methods, the bender elements technique. The authors' aim was to present the dynamics of a porous medium, in particular an extremely important passage of seismic waves that travel through the bulk of a medium. Nowadays, the application of the bender element (BE) technique to measure, e.g., small strain shear stiffness of soils in the laboratory is well recognized, since it allows for reliable and relatively economical shear wave velocity measurements during various laboratory experiments. However, the accurate estimation of arrival time during BE tests is in many cases unclear. Two different interpretation procedures (from the time domain) of BE tests in order to measure travel times of waves were examined. Those values were then used to calculate shear and compression wave velocities and elastic moduli. Results showed that the dynamic parameters obtained by the start-to-start method were always slightly larger (up to about 20%) than those obtained using the peak-to-peak one. It was found that the peak-to-peak method led to more scattered results in comparison to the start-to-start method. Moreover, the influence of the excitation frequency, the mean effective stress and the unloading process on the dynamic properties of the tested material was studied. In addition, the obtained results highlighted the importance of initial signal frequency and the necessity to choose an appropriate range of frequencies to measure the shear wave velocity in clayey soils.

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Section: Frequency Dependencymentioning

confidence: 99%

Dynamic Characterization of Cohesive Material Based on Wave Velocity Measurements

et al. 2016

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“…The shear wave velocity can be measured by determining the shear wave travel time between two transducers spaced at a known distance. Several methods have been developed by centrifuge modelers to generate shear waves in-flight, including the use of bender elements (Brandenberg et al 2006;Lee et al 2012;Kim 2010;Lee et al 2014) and air-hammers (Ghosh and Madabhushi 2002;Arulnathan et al 2000).…”

Section: Small Strain Shear Modulusmentioning

confidence: 99%

Effect of Duxseal on Horizontal Stress and Soil Stiffness in Small-Amplitude Dynamic Centrifuge Models

Cui

Heron

Marshall

2022

Geotechnical Testing Journal

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The constitutive behavior of soil is stress dependent. Therefore, geotechnical centrifuges are widely used to replicate full-scale stress fields, thereby ensuring the correct soil response within reduced-scale centrifuge models. A vibration absorbing material (such as Duxseal) is commonly employed to reduce the effect of reflected waves generated at the boundaries of rigid containers in dynamic centrifuge tests.However, such a material has the potential to deform laterally under the high horizontal stresses applied within centrifuge tests and consequently the initial at rest lateral earth pressure condition will not be maintained. A procedure to back-calculate the lateral earth pressure coefficient (𝐾) is presented in this paper.In addition, two experimental methods, which are implemented to evaluate 𝐾 by measuring the shear wave velocity from centrifuge-based air hammer testing and triaxial based bender element testing, are described.Results demonstrate that significant lateral earth pressure and soil stiffness reductions are observed within the upper soil region (top third of the model depth). In addition, the appropriate manipulation of the crosscorrelation method used to process shear wave signals is discussed and an empirical equation to predict the small strain shear modulus of the dry silica sand (HST95 Congleton sand) used in this study is provided.Outcomes of this study are directly applicable to small-amplitude dynamic centrifuge tests such as groundborne vibrations; some factors relating to large-amplitude seismic studies, such as soil inertial effects and

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“…Then, the modeling centrifuge was accelerated step by step up to 80 g, and the increment of acceleration in each step is 10 g. The model was maintained and lasted for 3 minutes at each step to ensure the consolidation of model at current overburden pressure. At 80 g, the model was detected by pre-shaking technique [20] and then excited by a one-dimensional sinusoidal input waves with 15 cycles and amplitude of about 0.4 g.…”

Section: Model Preparation and Test Proceduresmentioning

confidence: 99%

Centrifuge shaking table tests on effect of vertical drain systems for liquefied soil

Hung¹,

Lee²,

Tran³

2017

J. vibroeng.

Self Cite

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It was observed that liquefaction induced by earthquake causes series damages to buildings and threatens the people and their properties. From the past studies, a number of countermeasures were proposed to reduce the build-up of excess pore water pressure and to enhance the stiffness of the soil during earthquake. The vertical drain systems are well known methods and used as remediation against earthquake-induced soil liquefaction for many years. The purpose of the study is to investigate the effect of different vertical drain systems for the liquefiable soil by centrifuge modeling technique. The seismic behavior of liquefiable soil was performed firstly. The free field soil models were then prepared with alternatively arranged drain-belts and gravel-pile drains to investigate the effect of different vertical drain systems on the liquefiable soil. Several arrays of accelerometers, the pore water pressure transducers and displacement transducers were placed to monitor the shear wave propagation, the excitation and dissipation of pore water pressure. Displacement transducers were placed to measure the ground surface settlement. From the test results, it was observed that the vertical drain systems reduce the settlement and excess pore water pressure significantly. In the future, the vertical systems will be applied around the structure and the test results would give engineers suggestions to deal with the arrangements of drain-belts and gravel drains to reduce the damage during and after the earthquake.

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Shear wave velocity measurements and soil–pile system identifications in dynamic centrifuge tests

Cited by 19 publications

References 9 publications

Dynamic Characterization of Cohesive Material Based on Wave Velocity Measurements

Dynamic Characterization of Cohesive Material Based on Wave Velocity Measurements

Effect of Duxseal on Horizontal Stress and Soil Stiffness in Small-Amplitude Dynamic Centrifuge Models

Centrifuge shaking table tests on effect of vertical drain systems for liquefied soil

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