Shear Modulus and Damping Ratio of Sand–Gravel Mixtures Over a Wide Strain Range

2018 ◽  
Vol 23 (8) ◽  
pp. 1407-1440 ◽  
Author(s):  
Guoxing Chen ◽  
Zhenglong Zhou ◽  
Tian Sun ◽  
Qi Wu ◽  
Lingyu Xu ◽  
...  
Keyword(s):  
Shear Modulus ◽  
Damping Ratio ◽  
Strain Range

scholarly journals New Formulations for Dynamic Behavior of Sand-Waste Tire Mixtures in a Small Range of Strain Amplitudes

2017 ◽  
Vol 62 (1) ◽  
pp. 92-101 ◽  
Author(s):  
Ayse Edincliler ◽  
Ali Firat Cabalar ◽  
Abdulkadir Cevik ◽  
Haluk Isik
Keyword(s):  
Shear Modulus ◽  
Damping Ratio ◽  
Strain Range ◽  
Triaxial Tests ◽  
Small Range ◽  
Ratio Test ◽  
Waste Tire ◽  
Confining Pressures ◽  
Input Variables ◽  
Tire Crumbs

This paper describes the results of a series of cyclic triaxial tests on sand - waste tire mixtures, and applications of genetic programming (GP) and stepwise regression (SR) for the prediction of damping ratio and shear modulus of the mixtures tested. In the tests, shear modulus, and damping ratio of the geomaterials were measured for a strain range of 0.0001% up to 0.04%. The input variables in the developed GP and SR models are the waste tire content (0%, 10%, 20%, and 30%), waste tire type (tire crumbs or tire buffings), strain, and confining pressures (40 kPa, 100 kPa, and 200 kPa), and outputs are shear modulus and damping ratio. Test results show that the shear modulus and the damping ratio of the mixtures are strongly influenced by the waste tire inclusions. The performance of the proposed GP models (R2 = 0.95 for shear modulus, and R2 = 0.94 for damping ratio) are observed to be more accurate than that of the SR models (R2 = 0.87 for shear modulus, and R2 = 0.91 for damping ratio).

Simple shear testing of sensitive, very soft offshore clay for wide strain range

2009 ◽  
Vol 46 (11) ◽  
pp. 1277-1288 ◽  
Author(s):  
G. Lanzo ◽  
A. Pagliaroli ◽  
P. Tommasi ◽  
F. L. Chiocci
Keyword(s):  
Shear Modulus ◽  
Simple Shear ◽  
Damping Ratio ◽  
Soft Clay ◽  
Strain Range ◽  
Small Strain ◽  
Cyclic Shear ◽  
Wide Range ◽  
Equivalent Shear Modulus ◽  
Two Stages

Stiffness and damping properties of sensitive, very soft clay sediments of the Italian Adriatic continental shelf are determined by means of two series of cyclic simple shear tests (one with 12 stages and one with two stages). The apparatus used in this research is capable of investigating the stress–strain behaviour of the soil in a wide range of shear strains from about 0.0004% to 1%. Test results were expressed in terms of small-strain shear modulus (G0), normalized equivalent shear modulus (Geq/G0), and damping ratio (D) versus cyclic shear-strain amplitude (γc). These parameters were analyzed in the framework of existing literature by comparison with empirical correlations developed for onshore materials of different plasticity and, limited to G0, also for soft soils. The dependence of G0, Geq/G0–γc, and D–γc on factors such as void ratio, stress history, and loading cycles is analyzed and discussed.

scholarly journals Dynamic Properties of Sand-Sawdust Mixture for Modeling Deposit Soil

2019 ◽  
Vol 9 (18) ◽  
pp. 3863
Author(s):  
Pan ◽  
Li ◽  
Lu ◽  
Chen
Keyword(s):  
Shear Modulus ◽  
Shear Strain ◽  
Shaking Table Test ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Strain Range ◽  
Confining Pressure ◽  
Shaking Table ◽  
Triaxial Tests ◽  
Hysteresis Curve

Soil mixtures with various materials such as scraps of rubber tire, iron powder, and synthetic fibers have been widely used in civil engineering for experimental research or infrastructure construction and maintenance. However, these materials are not only expensive, but may also result in environmental concerns. In recent years, sawdust, because of its light-weight, inexpensive, and environmental friendly characteristics, has frequently been used in the shaking table test to adjust the dynamic properties of experimental soil. However, the dynamic properties of a sand-sawdust mixture for the shaking table test are still unclear. In this paper, the dynamic properties and the hysteresis curve characteristics of the sand-sawdust mixture as well as the influence of the sawdust content and confining pressure on the dynamic properties were studied using a series of consolidated drained dynamic triaxial tests. The test results show that, with the increase of the shear strain, the shape of the hysteresis loops changes from symmetrical willow-leaf to asymmetry sharp-leaf. For a given confining pressure, both the shear modulus and damping ratio decreases as the sawdust percentage increases. It was observed that, with an increase in confining pressure, the shear modulus increased while the damping ratio decreased slightly in the shear strain range of 10−3 to 7×10−3. It was also observed that the maximum shear modulus increased as the confining pressure increased, while the maximum damping ratio remained nearly constant. In addition, both the maximum shear modulus and the maximum damping ratio decreased as the sawdust content increased. Finally, the normalized shear modulus and damping ratio were established, which can be used in simulations using the shaking table test.

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.

Shear Modulus and Damping Ratio of Gravel Material

2011 ◽  
Vol 105-107 ◽  
pp. 1426-1432 ◽  
Author(s):  
De Gao Zou ◽  
Tao Gong ◽  
Jing Mao Liu ◽  
Xian Jing Kong
Keyword(s):  
Shear Modulus ◽  
Shear Strain ◽  
Strain Amplitude ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Dynamic Shear Modulus ◽  
Test Results ◽  
Dynamic Shear ◽  
Data Points ◽  
Shear Strain Amplitude

Two of the most important parameters in dynamic analysis involving soils are the dynamic shear modulus and the damping ratio. In this study, a series of tests were performed on gravels. For comparison, some other tests carried out by other researchers were also collected. The test results show that normalized shear modulus and damping ratio vary with the shear strain amplitude, (1) normalized shear modulus decreases with the increase of dynamic shear strain amplitude, and as the confining pressure increases, the test data points move from the low end toward the high end; (2) damping ratio increases with the increase of shear strain amplitude, damping ratio is dependent on confining pressure where an increase in confining pressure decreased damping ratio. According to the test results, a reference formula is proposed to evaluate the maximum dynamic shear modulus, the best-fit curve and standard deviation bounds for the range of data points are also proposed.

Experimental Study on Dynamic Characteristics of Ionic Soil Stabilizer Reinforcing Red Clay

2011 ◽  
Vol 374-377 ◽  
pp. 1391-1395
Author(s):  
Xue Song Lu ◽  
Wei Xiang
Keyword(s):  
Shear Modulus ◽  
Shear Strain ◽  
Dynamic Condition ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Natural Soil ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Red Clay ◽  
Soil Stabilizer

Based on the red clay of Wuhan reinforced by Ionic Soil Stabilizer, the red clay soil is treated by different matches of ISS at first, then is tested in the Atterberg limits test and dynamic triaxia test. The results show that the plastic index decreases, and the red clay were greatly improved under the dynamic condition, the maximum dynamic shear modulus ratio acquired an incensement of 27.72% on average after mixing the ISS into the red clay. In addition, It was concluded that the confining pressure influenced the dynamic shear modulus and damping ratio to a certain extent. Given the same strain conditions, with the incensement of confining pressure increases, the dynamic shear modulus increased and the damping ratio decreased. Moreover, when plotting the dynamic shear modulus versus the dynamic shear strain, the similar curve can be formed for both the natural soil and the modified one, the dynamic shear modulus monotonously decreased with the incensement of the dynamic shear strain. However, the value of dynamic shear modulus differed in the same shear strain between the natural soil and the soil modified by ISS.

Shear Modulus and Damping Ratio for Normally Consolidated Peat and Organic Clay in Hokkaido Area

2018 ◽  
Vol 36 (5) ◽  
pp. 3159-3171 ◽  
Author(s):  
Hirochika Hayashi ◽  
Takahiro Yamanashi ◽  
Hijiri Hashimoto ◽  
Masahiko Yamaki
Keyword(s):  
Shear Modulus ◽  
Damping Ratio ◽  
Organic Clay

An Investigation into Nonlinearity of Foundation Soil of Gravity Retaining Wall Based on an Inversion Method

2012 ◽  
Vol 204-208 ◽  
pp. 557-561
Author(s):  
Hong Yan Xi ◽  
Jun Hua Zhang ◽  
Jing Sun ◽  
Jing Li ◽  
You Qing Wang ◽  
...  
Keyword(s):  
Shear Modulus ◽  
Shear Strain ◽  
Damping Ratio ◽  
Retaining Walls ◽  
Earthquake Ground Motion ◽  
Inversion Method ◽  
Dynamic Shear Modulus ◽  
Foundation Soil ◽  
Residual Displacements ◽  
Dynamic Nonlinearity

Strong earthquake ground motion leads to residual displacements of gravity retaining walls. Since large deformation occurs in foundation soil, nonlinear mechanical behavior should not be neglected in numerical modeling. The inversion methodology in geophysics is borrowed here to study the nonlinearity, i.e. the variation of shear modulus and damping ratio with the increase of shear strain of soil. A simplified model for the seismic displacement of retaining walls is combined with a genetic algorithm for the inversion. The dynamic shear modulus and damping ratio curves, representing the nonlinear property of foundation soil in a centrifuge test for gravity retaining walls, is obtained by the use of an inversion scheme. The result indicates that, for low level of shear strain, the shear modulus is larger than that used in the literature, implying that the model ground may be stiffer than expectation. For high level of shear strain, the inverted damping ratio is larger than the conventional one, which has efficiently suppressed an overestimation of seismic displacements. It is also displayed that the inversion method is an effective way to obtain quantitatively the dynamic nonlinearity of foundation soil of gravity retaining walls.

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