scholarly journals Evaluation of the damping ratio of soils in a resonant column using different methods

2021 ◽  
pp. 101091
Author(s):  
Kunjari Mog ◽  
P. Anbazhagan
Keyword(s):  
Damping Ratio ◽  
Resonant Column

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 Experimental Investigation of Dynamic Characteristics of Subsea Sand-Silt Mixtures

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Tugen Feng ◽  
Yu Tang ◽  
Qiyenan Wang ◽  
Jian Zhang ◽  
Jian Song
Keyword(s):  
Cement Content ◽  
Damping Ratio ◽  
Shear Stiffness ◽  
Confining Pressure ◽  
Dynamic Responses ◽  
Resonant Column ◽  
Dynamic Shear ◽  
Column Tests ◽  
Mixture Ratio ◽  
Curing Age

In this paper, extensive resonant column tests were conducted to investigate dynamic responses of subsea sand-silt mixtures. The effects of confining pressure, mixture ratio, curing age, and cement content were evaluated. For the test condition considered in this study, the measured damping ratio is the smallest when the ratio of subsea sand to silt is in a range of 1.5 to 2.0. Moreover, unsolidified subsea sand-silt mixed at a ratio of 1.5 has almost the same maximum shear stiffness as the pure sand. For solidified subsea sand-silt mixture, cement can significantly increase the dynamic shear stiffness when the curing age is less than 14 days. However, the increase of the maximum dynamic shear stiffness is negligible when the curing age is longer than 14 days. When the cement content is 2%, the damping ratio of the solidified mixtures is very close to that of the unsolidified mixture. When the cement content is higher than 4%, the damping ratio of the solidified mixtures reduces significantly. This is mainly due to hydration reactions occurring in the solidified mixtures.

Measurement of dynamic properties of stiff specimens using ultrasonic waves

2011 ◽  
Vol 48 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Zahid Khan ◽  
Giovanni Cascante ◽  
M. Hesham El Naggar
Keyword(s):  
Shear Wave ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Ultrasonic Waves ◽  
Resonant Column ◽  
Reliable Determination ◽  
Cemented Sand ◽  
Wave Velocities ◽  
Shear Wave Velocities ◽  
Ultrasonic Equipment

The measurement of low-strain properties (wave velocity and damping ratio) of geomaterials is affected by equipment-generated delays, coupling of transducers, and wave reflections. This study presents a new technique to measure ultrasonic properties of stiff specimens accurately. Compressional-wave velocities in cylindrical rods of different lengths and materials were measured using different ultrasonic equipment. The error induced by different equipment was below 1% after the measurements were corrected by the equipment time delay. Shear-wave velocities of different materials were measured using ultrasonic transducers (frequency < 1 MHz) and a resonant column device (frequency < 200 Hz). The difference in shear-wave velocities was less than 4%, and the measured values are in agreement with published results for all tested materials. A new methodology based on the first two reflections of the main pulse has been developed to measure the damping ratio of stiff specimens using ultrasonic equipment. The ultrasonic measurements of the damping ratio compare well with resonant column results. A more reliable determination of the dynamic Poisson’s ratio of a cemented sand was achieved using corrected ultrasonic-wave velocities.

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 properties of some cohesive soils of Ontario

1981 ◽  
Vol 18 (3) ◽  
pp. 371-389 ◽  
Author(s):  
T. C. Kim ◽  
M. Novak
Keyword(s):  
Void Ratio ◽  
Dynamic Behaviour ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Dynamic Loads ◽  
Dynamic Shear Modulus ◽  
Cohesive Soils ◽  
Resonant Column ◽  
Dynamic Shear

The dynamic behaviour of some cohesive soils of southwestern Ontario is experimentally investigated using a resonant column apparatus. Attention is concentrated particularly on the dynamic shear modulus, Young's modulus, and damping ratio. The variation of these characteristics with void ratio, confining pressure, strain, and stress history is studied. Data are presented that can be utilized in the design of foundations and structures exposed to dynamic loads.

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