scholarly journals Evaluation of the shear wave velocity (VS) of an artificial carbonate sand obtained with the use of bender elements test

DYNA ◽  
2021 ◽  
Vol 88 (217) ◽  
pp. 211-219
Author(s):  
Samuel Felipe Mollepaza Tarazona ◽  
Bárbara Luiza Riz de Moura ◽  
Matias Faria Rodrigues ◽  
Maria Cascão Ferreira de Almeida ◽  
Marcio De Souza Soares de Almeida
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Mechanical Response ◽  
Near Field ◽  
Triaxial Tests ◽  
Dynamic Parameters ◽  
Bender Elements ◽  
Carbonate Sand ◽  
Confining Stress

Carbonate sand is characterized by the presence of fragile grains, which may influence their mechanical response due to the imposed loading; especially cyclic loading. The shear wave velocity (VS) provides relevant information for the design of foundation inserted in this type of soil, which can be obtained from laboratory tests with the use of bender elements (BE). This paper aims to evaluate the VS value of a carbonate sand from triaxial tests with BE using three methods in the time domain. The influence of loading, unloading and cycling on VS is also evaluated. The results confirmed that the confining stress affects the dynamic parameters. At higher stress levels, the signals aremore susceptible to the near field effects and the dynamic parameters are less influenced by cycling.

scholarly journals Bender elements in stiff cemented clay: shear wave velocity (Vs) correction by applying wavelength considerations

2019 ◽  
Vol 56 (7) ◽  
pp. 1034-1041 ◽  
Author(s):  
Qasim Khan ◽  
Sathya Subramanian ◽  
Dawn Y.C. Wong ◽  
Taeseo Ku
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Near Field ◽  
Shear Stiffness ◽  
Propagation Distance ◽  
Small Strain ◽  
Bender Element ◽  
Bender Elements ◽  
Sine Signal

For the quality control of cement mixing in clays, small-strain shear stiffness Gmax is now increasingly being used due to enhanced repeatability in shear wave velocity (Vs) measurements. These stiff cemented clays have higher resonant frequencies that require the use of higher input frequencies in bender element testing for reliable Vs measurements. However, the practical requirements for suitable signals (with minimal near-field effects and wave reflections) can often be difficult to implement. To facilitate such Vs measurements, the current study proposes a methodology that can correct Vs values corresponding to lower wave propagation distance to wavelength ratios (Ltt/λ) to more reliable values of Vs at reference Ltt/λ criterion suggested in previous studies (e.g., 2, 3.33, and 4). Two clay types are mixed with ordinary Portland cement and various mix ratios are utilized to cover a wider range of soil stiffnesses. Based on the collected database, it is found that the resulting fitting functions enable the reasonable estimation of the stabilized Vs values corresponding to the suggested Ltt/λ criterion regardless of the nature of the input sine signal.

scholarly journals Correlation between shear wave velocity and effective confining pressure using cyclic triaxial testing apparatus

2019 ◽  
Vol 92 ◽  
pp. 04009
Author(s):  
Guojun Liu ◽  
Noriyuki Yasufuku ◽  
Ryohei Ishikura ◽  
Qiang Liu
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Effective Stress ◽  
Shear Wave Velocity ◽  
Confining Pressure ◽  
Similar Rate ◽  
Bender Elements ◽  
Confining Stress ◽  
Liquefaction Resistance ◽  
Ground Shaking

The 2016 Kumamoto earthquakes struck Kumamoto and Ōita regions and caused several devastating liquefaction induced damages. The primary damage was due to the extreme ground shaking of the foreshock and main shock sequence. Therefore, it is essential to develop a quick reliable approach with a high accuracy to assess the ground situation after foreshock or several shocks. Velocity of small shear wave (Vs) was widely used for evaluating the potential liquefaction. This study investigates the possibility of using Vs as a new indicator of the stress state in the soil after earthquake and evaluation of post liquefaction resistance of soil. Cyclic tri-axial apparatus equipped with bender elements were used to conduct two consecutives liquefaction tests on sandy soil. The Vs measured by bender elements was discussed on the relationship with effective stress during the liquefying processes. The results showed that for the sandy soils, a) Vs could not clearly reflect the significant reduction in resistance at re-liquefaction stages by directly comparing the Vs at the end of consolidation between first and stages, b) The shear wave velocity is significantly affected by effective confining pressure c) the shear wave velocity of 190 m/s was at confining pressure of 100 kPa. The shear wave velocity reaches to after 100 m/s after consolidations and re-consolidations. The shear wave velocity was found to reduce to 100 m/s when the effective confining stress reaches to 0 and to around 25 m/s when the double amplitude reaches to 5%; d) the velocity and effective stress decreases with a similar rate in liquefying process.

Shear Strength Monitoring System Based on Measurement of Shear Wave Velocity and Moisture Content

2014 ◽  
Vol 635-637 ◽  
pp. 750-754
Author(s):  
Peng Hu ◽  
Qing Li ◽  
Yi Wei Xu ◽  
Nan Ying Shentu ◽  
Quan Yuan Peng
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Shear Wave ◽  
Monitoring System ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Bender Elements ◽  
Strength Measurement ◽  
Soil Shear Strength ◽  
The Relationship

Expound the importance of soil shear strength measurement at mudslide hidden point to release the loss caused by the disaster, explain the relationship between shear wave velocity, moisture content and shear strength, design the shear strength monitoring system combining the shear wave velocity measured by Piezoelectric bender elements and moisture content.

Surface-mounted bender elements for measuring horizontal shear wave velocity of soils

2008 ◽  
Vol 9 (11) ◽  
pp. 1490-1496 ◽  
Author(s):  
Yan-guo Zhou ◽  
Yun-min Chen ◽  
Yoshiharu Asaka ◽  
Tohru Abe
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Horizontal Shear ◽  
Bender Elements

Discussion “Measuring Shear Wave Velocity Using Bender Elements” by Leong, E. C., Yeo, S. H., and Rahardjo, H.

2006 ◽  
Vol 29 (5) ◽  
pp. 100382 ◽  
Author(s):  
L David Suits ◽  
TC Sheahan ◽  
J-S Lee ◽  
J Carlos Santamarina
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Bender Elements

Analysis on the Bias of Seismic Ground Motion Prediction in a Shallow Stiff-Soil Site by LSSRL-1 Program

2014 ◽  
Vol 915-916 ◽  
pp. 18-21
Author(s):  
Zhuo Shi Chen ◽  
Xiao Ming Yuan ◽  
Shang Jiu Meng
Keyword(s):  
Shear Wave ◽  
Ground Motion ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Dynamic Parameters ◽  
Ground Motion Prediction ◽  
Blind Prediction ◽  
Soil Site ◽  
Parkfield Earthquake ◽  
Stiff Soil

The main causes of the ground motion blind prediction bias are the variability of the adopted program, the shear-wave velocity of the site, and the soil nonlinear dynamic parameters. By considering the variability of shear-wave velocity and the dynamic parameters, this essay used LSSRLI-1 Codes and Mw6.0 seismic record of Parkfield earthquake to calculate ground responses of 9 different conditions at Turkey Flat site. The authors believe that the variability of shear-wave velocity caused the dominant impact to the blind prediction of this shallow stiff-soil site. That impact is much greater than that of the dynamic parameters. LSSRLI-1 program may either underestimate the ground response of the shallow stiff-soil site or may overestimate it, so we should combine the specific site conditions and a large amounts of data to do the further analysis.

Consolidation characteristics of hydraulically deposited tailings obtained from shear wave velocity (Vs) measurements in triaxial and oedometric cells with piezoelectric ring-actuator technique (P-RAT)

2020 ◽  
pp. 1-14 ◽  
Author(s):  
Louis-Philippe Grimard ◽  
Mourad Karray ◽  
Michael James ◽  
Michel Aubertin
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Void Ratio ◽  
Cone Penetration ◽  
Confining Stress ◽  
Overconsolidation Ratio ◽  
Cone Penetration Testing ◽  
Tailings Impoundment ◽  
P Rat

This paper presents the main results of a laboratory study of the use of shear wave velocity, Vs, to characterize hydraulically deposited tailings on the basis of density (void ratio), mean effective stress, and overconsolidation ratio. Tailings specimens from a gold mine in western Quebec were prepared in triaxial and oedometric cells in a manner that simulates hydraulic deposition. The specimens were consolidated isotropically and anisotropically (stress ratio, K of 0.38). Vs measurements were performed at each load increment using the piezoelectric ring-actuator technique (P-RAT). Correlations relating shear wave velocity to the void ratio, confining stress, and overconsolidation ratio of the tailings are presented. These laboratory correlations can be used for the characterization of the tailings by in situ Vs measurement. The application of these correlations to seismic cone penetration testing in an actual tailings impoundment is also presented.

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