scholarly journals Characterization of the Dynamic Properties of Clay–Gravel Mixtures at Low Strain Level

2020 ◽  
Vol 12 (4) ◽  
pp. 1616 ◽  
Author(s):  
Xianwen Huang ◽  
Aizhao Zhou ◽  
Wei Wang ◽  
Pengming Jiang
Keyword(s):  
Shear Modulus ◽  
Shear Strain ◽  
Mechanical Performance ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Strain Level ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Gravel Content

In order to support the dynamic design of subgrade filling engineering, an experiment on the dynamic shear modulus (G) and damping ratio (D) of clay–gravel mixtures (CGMs) was carried out. Forty-two groups of resonant column tests were conducted to explore the effects of gravel content (0%, 10%, 20%, 30%, 40%, 50%, and 60%, which was the mass ratio of gravel to clay), gravel shape (round and angular gravels), and confining pressure (100, 200, and 300 kPa) on the dynamic shear modulus, and damping ratio of CGMs under the same compacting power. The test results showed that, with the increase of gravel content, the maximum dynamic shear modulus of CGMs increases, the referent shear strain increases linearly, and the minimum and maximum damping ratios decrease gradually. In CGMs with round gravels, the maximum dynamic shear modulus and the maximum damping ratio are greater, and the referent shear strain and the minimum damping ratio are smaller, compared to those with angular gravels. With the increase of confining pressure, the maximum dynamic shear modulus and the referent shear strain increase nonlinearly, while the minimum and maximum damping ratios decrease nonlinearly. The predicting equation for the dynamic shear modulus and the damping ratio of CGMs when considering confining pressure, gravel content, and shape was established. The results of this research may put forward a solid foundation for engineering design considering low-strain-level mechanical performance.

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.

scholarly journals Study on Dynamic Characteristics of Rubber-Red Clay Mixtures

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Kaisheng Chen ◽  
Qinqin Wang ◽  
Dipu Luo ◽  
Bo Zhou ◽  
Kun Zhang
Keyword(s):  
Particle Size ◽  
Shear Modulus ◽  
Vibration Frequency ◽  
Damping Ratio ◽  
Rubber Particle ◽  
Confining Pressure ◽  
Dynamic Strain ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Red Clay

Rubber powder formed from discarded tire rubber is mixed with red clay to form a rubber-red clay mixture. The dynamic triaxial test was carried out on the mixtures under different conditions. The effects of rubber content, rubber particle size, moisture content of mixed soil, compactness, confining pressure, and vibration frequency on shear strain relation, dynamic shear modulus, and damping ratio of the mixture were investigated. The results show that under the same dynamic strain, the dynamic shear stress-strain curve of rubber mixed soil decreases with the increase in rubber particle content and moisture content and decrease in rubber particle size. On the other hand, it increases with the increase in compactness, confining pressure, and vibration frequency, and as the dynamic strain increases, the τd-γd curve becomes more nonlinear. In addition, with the increase in the rubber particle content, the dynamic shear modulus decreased while the damping ratio increased. When the content was 2%, the change was fastest. After continued addition, it gradually became stable, and when the decrease in rubber particle size also shows the same pattern, 2.00 mm rubber-red clay mixture shows better structure. The water content has great influence on dynamic shear modulus and damping ratio of rubber-red clay mixtures. With the increase in compactness, confining pressure, and vibration frequency, the interaction between mixed soil particles was enhanced, the dynamic shear modulus increased, and the damping ratio decreased.

scholarly journals Effect of Sand Fouling on the Dynamic Properties and Volume Change of Gravel During Cyclic Loadings

2020 ◽  
Author(s):  
Meysam Bayat
Keyword(s):  
Shear Modulus ◽  
Shear Strain ◽  
Dynamic Behavior ◽  
Volume Change ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Triaxial Tests ◽  
Practical Applications ◽  
Large Shear Strain

Understanding the factors that influence the dynamic behavior of granular soils during cyclic loading is critical to infrastructure design. Previous research has lacked quantitative study of the effects of fouling index (FI), mean effective confining pressure, relative density, shear strain level and anisotropic consolidation, especially when the effective vertical stress is lower than the effective horizontal stress on the dynamic behavior of gravelly soils. The objective of the present study was to evaluate the dynamic behavior and volume change of both clean and fouled specimens for practical applications. To this end, cyclic triaxial tests with local strain measurements under both isotropic and anisotropic confining conditions were conducted. It is found that the fouled specimen with 50 % sand (i.e. the specimen which contains 50 % gravel and 50 % sand) has the highest shear modulus at low shear strain levels and the largest volume reduction and damping ratio at large shear strain levels. The results of tests indicate that the effect of fouling index on the shear modulus is reduced at large shear strain levels. Volumetric contraction due to the increase in mean effective confining pressure is more significant at large shear strain levels. The results also indicate that the stiffness of the specimens under anisotropic compression mode are larger than those in extension or isotropic mode.

Research on the Dynamic Deformation Characteristics of Tailings Silt in Zhuziqing Tailings Dam

2012 ◽  
Vol 524-527 ◽  
pp. 459-465
Author(s):  
Jian Bin Xie ◽  
Wen Lian Liu ◽  
Lin Hua Shi ◽  
Guo Hai Zhang ◽  
Jie Zhang
Keyword(s):  
Mechanical Properties ◽  
Shear Modulus ◽  
Damping Ratio ◽  
Physical And Mechanical Properties ◽  
Dynamic Strength ◽  
Confining Pressure ◽  
Standard Penetration Test ◽  
Dynamic Shear Modulus ◽  
Tailings Dam ◽  
Dynamic Shear

In this paper, it has been studied that types and mechanical properties of tailings silt in Zhuziqing tailings dam based on the Zhuziqing tailings’ deposition characteristics, particles size distribution test, physical and mechanical properties test. Then it has been studied subsequently by the dynamic triaxial test, wave velocity test and standard penetration test for tailings silt that the dynamic characteristics, dynamic strength and vibration liquefaction of the tailing silt. Results show that the tailings silt in tailings pond is graded well. Under the condition of isotropic or anisotropic consolidation, dynamic shear modulus of tailings silt increase as the dynamic shear strain decreasing and increase as the increase of confining pressure or consolidation ratio. But the variation law on damping ratio of tailings silt is just opposite to that of dynamic shear modulus. Results also show that there is more liquefied possibility over the seventh sub-dam in the tailings dam, and the liquefied possibility position locates at the place from new sub-dam to deposited beach in tailing pond.

scholarly journals EXPERIMENTAL STUDY ON THE DYNAMIC SHEAR MODULUS AND DAMPING RATIO OF SATURATED SAND UNDER CYCLIC LOADING

2021 ◽  
Vol 55 (5) ◽  
Author(s):  
Jian Zhang ◽  
Jiuting Cao ◽  
Sijie Huang ◽  
Baocun Shi
Keyword(s):  
Shear Stress ◽  
Shear Modulus ◽  
Shear Strain ◽  
Vibration Frequency ◽  
Damping Ratio ◽  
Test System ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Saturated Sand ◽  
Good Agreement

Initial shear stress is inevitable in actual engineering slopes, subgrades and foundations, and soils exhibit different dynamic characteristics under the influence of initial shear stress. Using a dynamic triaxial test system, this study explores the dynamic shear modulus and damping ratio of saturated sand from Wenchuan, investigates the effects of the initial shear stress and vibration frequencies on the dynamic shear modulus and damping ratio of saturated sand and proposes a normalised dynamic shear modulus formula that considers the initial shear stress and vibration frequency. Results show a threshold dynamic shear strain of the saturated sand. When the dynamic shear strain is below this threshold, the dynamic shear modulus significantly increases with the initial shear stress and vibration frequency. Otherwise, the influence of the initial shear stress and vibration frequency gradually decreases and eventually stabilises. The initial shear stress significantly affects the normalised dynamic shear modulus/strain curves where a larger initial shear stress corresponds to a higher curve. Meanwhile, the vibration frequency only exerts a slight influence. The curves under different frequencies are generally within the same band and fall near the Seed upper envelope. The initial shear stress also has a significant influence on the damping ratio where a larger initial shear stress corresponds to a smaller damping ratio. On the basis of the experimental results, a normalised dynamic shear modulus/shear strain formula that considers the influence of the initial shear stress and vibration frequency is established. Fitting results indicate that this formula shows good agreement with the test data.

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.

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.

Experimental Study on Dynamic Shear Modulus and Damping Ratio of Soft Soils in Binhu New District of Hefei

2013 ◽  
Vol 405-408 ◽  
pp. 1957-1960 ◽  
Author(s):  
Xin Lin Wan ◽  
Dao Lin Yang
Keyword(s):  
Shear Modulus ◽  
Soft Soil ◽  
Damping Ratio ◽  
Column Experiment ◽  
Reference Value ◽  
Confining Pressure ◽  
Dynamic Shear Modulus ◽  
Design Calculation ◽  
Construction Technology ◽  
Dynamic Shear

The article through to free vibration column experiment research to soft soil of Binhu new district of Hefei, The data and curves are given for four types of soil dynamic shear modulus and damping ratio with shear strain and draw rules of different size of confining pressure on the dynamic shear modulus and damping ratio of soil. For hefei binhu new area soft soil of the physical and mechanical characteristics, select the optimal soft foundation treatment scheme, practical design calculation model is set up, and perfect the construction technology measures, the article has some reference value.

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