Study on Dynamical Modulus and Damping Ratio of Lime-Treated Soil

2012 ◽  
Vol 487 ◽  
pp. 534-538
Author(s):  
Min Wang ◽  
Ling Wei Kong ◽  
Xiao Yan Wang
Keyword(s):  
Laboratory Tests ◽  
Dynamic Stress ◽  
General Trend ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Expansive Soil ◽  
Confining Pressure ◽  
Test System ◽  
Expansive Clay ◽  
Number Of Cycles

In order to study dynamic properties of lime-treated expansive clay, a comprehensive series of laboratory tests were conducted via dynamic triaxial test system. The influences of factors such as moisture content, confining pressure, vibration frequency, consolidation ratio and the number of cycles on dynamic characteristics were discussed. It is found that the dynamic stress-strain curves of lime-treated expansive clay show the general trend of hyperbola. Compared with the remoulded expansive soil, the bearing capacity of lime improved expansive soil is higher than remolded soil.

A Study on Dynamic Properties of Cement-Stabilized Soils

2011 ◽  
Vol 243-249 ◽  
pp. 2050-2054 ◽  
Author(s):  
Pei Hsun Tsai ◽  
Sheng Huoo Ni
Keyword(s):  
Shear Modulus ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Test Results ◽  
Resonant Column Test ◽  
Stabilized Soil ◽  
Shearing Strain ◽  
Relationship Of ◽  
The Relationship

In this paper the dynamic property (shear modulus and damping ratio) of cement-stabilized soil is studied with using the resonant column test. The amount of cement admixed, the magnitude of confining pressure, and shearing strain amplitude are the parameters considered. Test results show that the maximum shear modulus of cement-stabilized soil increases with increasing confining pressure, the minimum damping ratio decreases with increasing confining pressure. The shear modulus of cement-stabilized soil decreases with increasing shearing strain while the damping ratio increases with increasing shearing strain. In the paper the relationship of shear modulus versus shearing strain is fitted into the Ramberg-Osgood equations using regression analysis.

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.

Test Study on the Dynamic Parameters of Compound Composite Foundation

2012 ◽  
Vol 450-451 ◽  
pp. 1548-1552
Author(s):  
Na Wang ◽  
Zhen Feng ◽  
Yong Da ◽  
Wei Lin
Keyword(s):  
Regression Analysis ◽  
Seismic Design ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Composite Foundation ◽  
Dynamic Parameters ◽  
Simple Method ◽  
Test Study ◽  
Wide Range

Influence of factors such as displacement ratio and confining pressure on the dynamic properties of composite specimen with GC pile and CFG pile was studied under a wide range of strains by regression analysis，a simple method for calculating the dynamic elastic modulus and damping ratio is Proposed and an empirical formula considering the mentioned factors above is also presented to provide a elementary reference for anti-seismic design of composite foundations with GC piles and CFG piles.

scholarly journals Laboratory Characterization of a Compacted–Unsaturated Silty Sand with Special Attention to Dynamic Behavior

2020 ◽  
Vol 10 (7) ◽  
pp. 2559
Author(s):  
Andrzej Głuchowski ◽  
Zdzisław Skutnik ◽  
Marcin Biliniak ◽  
Wojciech Sas ◽  
Diego Lo Presti
Keyword(s):  
Shear Modulus ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Silty Sand ◽  
Triaxial Tests ◽  
Bender Element ◽  
State Dependent ◽  
Laboratory Characterization ◽  
Dynamic Excitations

The dynamic properties of compacted non-cohesive soils are desired not only because of the risk of natural sources of dynamic excitations such as earthquakes, but mostly because of the anthropogenic impact of machines that are working on such soils. These soils are often unsaturated, which positively affects the soil’s mechanical properties. The information about the values of these parameters is highly desirable for engineers. In this article, we performed a series of tests, including oedometric tests, resonant column tests, bender element tests, and unsaturated triaxial tests, to evaluate those characteristic parameters. The results showed that sandy silt soil has a typical reaction to dynamic loading in terms of shear modulus degradation and the damping ratio curves’ characteristics, which can be modeled by using empirical equations. We found that the compaction procedure caused an over-consolidation state dependent on the moisture content during compaction effort. The article analyzed the soil properties that impact the maximum shear modulus G0 value. Those properties were suction s, confining pressure σ3, and compaction degree represented by the void ratio function f(e).

An archive of data from resonant column and cyclic torsional shear tests performed on Italian clays

2020 ◽  
pp. 875529302093669
Author(s):  
Johann Facciorusso
Keyword(s):  
Earthquake Engineering ◽  
Multiple Testing ◽  
Laboratory Tests ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Large Data ◽  
Dynamic Parameters ◽  
Data Set ◽  
Geotechnical Earthquake Engineering ◽  
Geotechnical Tests

Measurement of soil properties under cyclic and dynamic loading conditions is a critical task in the solution of most geotechnical earthquake engineering problems. The main dynamic properties of soils are usually expressed in terms of shear modulus, G, and damping ratio, D, and they are generally obtained from laboratory tests at different strain levels. Dynamic geotechnical problems often require a site-level or territorial approach involving a considerable number of dynamic laboratory tests that might be too expensive and time-consuming. Thus, it is a common practice to use empirical relationships between dynamic parameters and measurements from routine geotechnical tests. Therefore, the availability of a large and reliable archive of multiple testing results constitutes a fundamental step for geotechnical earthquake engineers and researchers. To this aim, a large data-set of the index and dynamic parameters measured from 170 undisturbed clay samples obtained from 90 sites in Central and Northern Italy is made available, and its use and application are further described and discussed.

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.

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.

ANALYSIS OF DYNAMIC STRESS-STRAIN RELATIONSHIP OF LOESS

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5559-5565
Author(s):  
HONGJIAN LIAO ◽  
ZHIGANG ZHANG ◽  
CHUNMING NING ◽  
JIAN LIU ◽  
LI SONG
Keyword(s):  
Residual Strain ◽  
Dynamic Stress ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Constitutive Relationship ◽  
Triaxial Tests ◽  
Stress And Strain ◽  
Test Results ◽  
Relationship Model ◽  
Strain Relationship

This paper aims to study dynamic properties of loess. This study is helpful to the subject on how to avoid or decrease the seismic disasters on loess ground. Dynamic triaxial tests are carried out with saturated remoulded soil samples taken form loess sites in Xi'an, China. Dynamic stress and strain relationship as well as the rule of the accumulated residual strain are obtained from the test results. Linear relationship between accumulated residual strain and vibration circle under constant amplitude circular loading is presented. A hypothesis about the accumulated residual strain is proposed. 1D dynamic constitutive relationship model which can well describe the real relationship between dynamic stress and strain under irregular dynamic loading is established. Numerical program with this model is developed and an example is tested. Numerical results of hysteresis loop, accumulated residual strain, amplitude of dynamic stress and damping ratio show good agreement with test results. It is indicated that the hypothesis of accumulated residual strain and the 1D dynamic constitutive relationship model can accurately simulate the dynamic triaxial tests of saturated remoulded loess.

scholarly journals Small-Strain Dynamic Properties of Lean Cemented Sand and Gravel Materials under Different Cementing Agent Contents

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Jie Yang ◽  
Xin Cai ◽  
Yangong Shan ◽  
Miaomiao Yang ◽  
Xingwen Guo ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Small Strain ◽  
Triaxial Tests ◽  
Dynamic Shear Modulus ◽  
Engineering Applications ◽  
Cemented Sand ◽  
Sand And Gravel ◽  
Cementing Agent

Lean cemented sand and gravel (LCSG) materials are increasingly being used in dams, embankments, and other civil engineering applications. Therefore, their mechanical properties and stress-strain behavior should be systematically understood. In this study, the small-strain dynamic properties of LCSG materials were examined. A series of dynamic triaxial tests were performed to investigate the effects of the confining pressure and cementing agent content of the material on its dynamic shear modulus (Gd) and damping ratio (λ). The results show that Gd increased and λ decreased with increasing confining pressure and cementing agent content; however, under the same confining pressure and cementing agent content, Gd decreased gradually in accordance with shear strain. Furthermore, new expressions were derived for Gd and λ, as well as for their maxima. The results of this study could provide a reference for practical engineering applications, including the construction of dams using LCSG materials.

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