Effects of Particle Grading and Stress State on Strain-Nonlinearity of Shear Modulus and Damping Ratio of Sand Evaluated by Resonant-Column Testing

2018 ◽  
Vol 24 (12) ◽  
pp. 1886-1912 ◽  
Author(s):  
Haiwen Li ◽  
Kostas Senetakis
Keyword(s):  
Stress State ◽  
Shear Modulus ◽  
Damping Ratio ◽  
Resonant Column ◽  
Column Testing

scholarly journals Evaluation of Dynamic Properties of Sodium-Alginate-Reinforced Soil Using A Resonant-Column Test

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2743
Author(s):  
Seongnoh Ahn ◽  
Jae-Eun Ryou ◽  
Kwangkuk Ahn ◽  
Changho Lee ◽  
Jun-Dae Lee ◽  
...  
Keyword(s):  
Shear Modulus ◽  
Sodium Alginate ◽  
Shear Failure ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Reinforced Soil ◽  
Resonant Column ◽  
Column Test ◽  
Alginate Solution ◽  
Resonant Column Test

Ground reinforcement is a method used to reduce the damage caused by earthquakes. Usually, cement-based reinforcement methods are used because they are inexpensive and show excellent performance. Recently, however, reinforcement methods using eco-friendly materials have been proposed due to environmental issues. In this study, the cement reinforcement method and the biopolymer reinforcement method using sodium alginate were compared. The dynamic properties of the reinforced ground, including shear modulus and damping ratio, were measured through a resonant-column test. Also, the viscosity of sodium alginate solution, which is a non-Newtonian fluid, was also explored and found to increase with concentration. The maximum shear modulus and minimum damping ratio increased, and the linear range of the shear modulus curve decreased, when cement and sodium alginate solution were mixed. Addition of biopolymer showed similar reinforcing effect in a lesser amount of additive compared to the cement-reinforced ground, but the effect decreased above a certain viscosity because the biopolymer solution was not homogeneously distributed. This was examined through a shear-failure-mode test.

scholarly journals Dynamic Properties of Clean Sand Modified with Granulated Rubber

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Dervis Volkan Okur ◽  
Seyfettin Umut Umu
Keyword(s):  
Shear Modulus ◽  
Dynamic Characteristics ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Relative Size ◽  
Cyclic Behavior ◽  
Damping Capacity ◽  
Resonant Column ◽  
Strain Dependent

Waste automobile tires are used as additives or replacements instead of traditional materials in civil engineering works. In geotechnical engineering, tires are shredded to certain sizes and mixed with soil, especially used as backfill material behind retaining walls or fill material for roadway embankments. Compared to soil, rubber has high damping capacity and low shear modulus. Therefore, it requires the determination of the dynamic characteristics of rubber/soil mixtures. In this paper, the cyclic behavior of recycled tire rubber and clean sand was studied, considering the effects of the amount and particle size of the rubber and confining stresses. A total of 40 stress-controlled tests were performed on an integrated resonant column and dynamic torsional shear system. The effects of the relative size and proportion of the rubber on the dynamic characteristics of the mixtures are discussed. The dynamic properties, such as the maximum shear modulus, strain-dependent shear modulus, and damping ratio, are examined. For practical purposes, simple empirical relationships were formulated to estimate the maximum shear modulus and the damping ratio. The change in the shear modulus and damping ratio with respect to shear strain with 5% of rubber within the mixture was found to be close to the behavior of clean sand.

DEGRADATION EFFECT OF SEAWATER ON THE LONG-TERM DYNAMIC BEHAVIOR OF ARTIFICIALLY CEMENTED SAND

2013 ◽  
Vol 07 (04) ◽  
pp. 1350031 ◽  
Author(s):  
BO LI ◽  
YUANQIANG CAI ◽  
XIANGWU ZENG ◽  
LINYOU PAN
Keyword(s):  
Shear Modulus ◽  
Dynamic Behavior ◽  
Tap Water ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Triaxial Tests ◽  
Resonant Column ◽  
Cyclic Triaxial Tests ◽  
Cemented Sand

The dynamic behavior of lightly cemented sand under long-term seawater attack was evaluated in this study. Resonant column and cyclic triaxial tests were employed to investigate the evolution of the shear modulus and damping ratio of cemented sand with respect to soaking period (SP), confining pressure, and cement content (CC). The results of this study show that the cementation of the sand is affected by soaking in seawater to a greater extent than by soaking in tap water. The shear modulus of the cemented sand soaked in seawater was smaller than that of the cemented sand soaked in tap water. The damping ratio increased significantly, as the SP increased and was greater for the cemented sand soaked in seawater than for the cemented sand soaked in tap water. The dynamic behavior of nonhomogenous specimens was examined. Crystallization of salts could be clearly observed and probably explains the evolution of the dynamic behavior of the cemented sand. Finally, the shear modulus was fitted using Rollins' Law [Rollins et al., 1998], which demonstrates that the parameters used in the equation can be reasonably fitted linearly over a range of SPs.

scholarly journals Resonant Column Test on the Frozen Silt Soil Modulus and Damping at Different Temperatures

2017 ◽  
Author(s):  
Xiaobo Yu ◽  
Rui Sun ◽  
Xiaoming Yuan ◽  
Zhuoshi Chen ◽  
Jiuqi Zhang
Keyword(s):  
Shear Modulus ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Negative Temperature ◽  
Frozen Soil ◽  
Resonant Column ◽  
Engineering Construction ◽  
Resonant Column Test ◽  
Triaxial Apparatus ◽  
Different Temperatures

The shear modulus and damping ratio of frozen soil are thebasic parameters of its dynamic properties and are often testedwith the dynamic triaxial apparatus. However, the resonantcolumn apparatus is more suitable for the testing at the microstrainlevel. A resonant column apparatus was here used toidentify the varying modes with negative temperature of theinitial shear modulus, modulus ratio, and damping ratio of frozensilt. Correction factor curves indicate that the temperaturehas a great effect on the shear modulus and damping ratio offrozen silt. The curves also show that, within the sensitive stage,the temperature significantly affects the modulus and damping.Within the insensitive stage, the modulus and dampingwere insensitive to the temperature. The experimental resultsand analysis given here provide support for improving seismicdesign codes and offer reasonable parameters for seismicresponse analysis in engineering construction in cold regions.

Difference between current and voltage measurements in resonant-column testing

2003 ◽  
Vol 40 (4) ◽  
pp. 806-820 ◽  
Author(s):  
Giovanni Cascante ◽  
John Vanderkooy ◽  
Wilson Chung
Keyword(s):  
Transfer Function ◽  
Shear Strain ◽  
Damping Ratio ◽  
Complex Impedance ◽  
Input Voltage ◽  
Nonlinear Behaviour ◽  
Resonant Column ◽  
Maximum Shear Strain ◽  
Column Testing

The resonant-column test is one of the most common procedures for dynamic characterization of soils (American Society for Testing and Materials standard). The test procedures require the measurement of the current flowing through the driving coils. In many cases, however, the input voltage has been measured and the results analyzed as a traditional current measurement. In this paper, the difference between current and voltage measurements is clarified; specifically, a new transfer function is presented for the analysis of data when the input voltage is measured. The new model is evaluated by testing three aluminum probes. Wave velocities computed from voltage and current measurements are similar; however, damping ratios are significantly overestimated if voltage-based measurements are analyzed with the standard procedures because the motion of the magnets induces an opposite voltage in the coils. Results from voltage and current measurements agree only if the new transfer function is used for the analysis of voltage data. Exploratory results for a dry-sand specimen, tested under different shear-strain levels (maximum shear strain γmax < 10–3), demonstrate the effect of nonlinear behaviour on current and voltage measurements. Current-based measurements are recommended because they do not require the evaluation of the complex impedance of the driving coils. Furthermore, current-based measurements are more precise, especially for the characterization of specimens that have low resonant frequencies.Key words: resonant-column testing, damping ratio, attenuation, mechanical waves, shear modulus, wave velocity.

Dynamic Shear Modulus and Damping Ratio of Waste Granular Rubber and Cement Soil Mixtures

2011 ◽  
Vol 243-249 ◽  
pp. 2091-2094
Author(s):  
Zhao Yu Wang ◽  
Guo Xiong Mei ◽  
Xin Bao Yu
Keyword(s):  
Shear Modulus ◽  
Dynamic Modulus ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Dynamic Shear Modulus ◽  
Resonant Column ◽  
Ratio Increase ◽  
Confining Pressures ◽  
Soil Mixtures ◽  
Cement Soil

In this study a resonant column apparatus was used to obtain the shear modulus and damping ratio of the waste granular rubber and cement soil mixtures. Specimens were tested for different rubber contents and confining pressures. Experiments show that with the rubber increased, the damping ratio of the rubber and cement soil mixtures increases, dynamic modulus decreases. When the confining pressure increases, the shear modulus of rubber and cement soil mixtures increase gradualy, damping ratio increase slightly.

Small strain shear modulus and damping ratio of two unsaturated lateritic sandy clays

2020 ◽  
Author(s):  
C.W.W. Ng ◽  
Obed Takyi Bentil ◽  
Chao Zhou
Keyword(s):  
Shear Modulus ◽  
Damping Ratio ◽  
Small Strain ◽  
Resonant Column ◽  
Column Tests ◽  
Small Strain Shear Modulus ◽  
Confining Pressures ◽  
The Difference ◽  
Elastic Threshold ◽  
Scanning Electron

In this study, resonant column tests carried out to investigate the influence of suction on the shear modulus and damping ratio of two compacted lateritic sandy clays from Ghana (GL) and Nigeria (NL) are reported. Each type of soils was tested under two confining pressures and at three suctions. The microstructure of the soils was also studied through a scanning electron microscope. It is found that the effects of suction on maximum shear modulus (G<u><sub></u>0<u></sub></u>) are about 10% larger for GL than NL, mainly due to the existence of smaller aggregates in GL. Moreover, an increase in suction from 0 to 300 kPa for both soils resulted in a lower elastic threshold shear strain, different from the behaviour of other soils reported in the literature. The uniqueness of lateritic soils is likely attributed to their high sesquioxide content and much larger aggregates, which shrink upon an increase in suction. Drying of specimens from 0 to 300 kPa resulted in an increase of about 22% and 100% in initial damping ratio (D<sub>0</sub>) for GL and NL, respectively. The difference in D<sub>0</sub> for GL and NL and is attributed to larger aggregation of NL because of its higher iron sesquioxide content, leading to more cladding

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