Nonlinear dynamic properties of silty clay from Warsaw area

Abstract In this work, the small-strain and nonlinear dynamic properties of silty clay samples were studied by means of the low- and high-amplitude resonant column (RC) tests at various mean effective stresses (p’). The tested specimens were collected from the centre of Warsaw, district Śródmieście. Initially, the low-amplitude tests (below 0.001%) were conducted. Subsequently, the nonlinear testing was performed, at shearing strains greater than 0.001%. These tests were carried out in order to receive the dynamic properties of silty clay specimens in the nonlinear shear strain range. The small-strain material damping ratios (Dmin) of silty clay samples were also measured during the low-amplitude resonant column testing. The results show that increasing shear strain (γ) above the elastic threshold (γte) causes a decrease of the shear modulus (G) and normalized shear modulus (G/Gmax) of analyzed soil samples. Simultaneously, it is observed a increase of its damping ratio (D) and normalized damping (D/Dmin) with increasing shear strain (γ). Predictive equations for estimating normalized shear modulus and material damping of silty clay soils were presented here as well. The equations are based on a modified hyperbolic model and a statistical analysis of the RC tests results. The influence of unloading process on dynamic properties of the tested material was also discussed in the paper.

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Shear modulus and material damping of municipal solid waste based on large-scale cyclic triaxial testing

Canadian Geotechnical Journal ◽

10.1139/t07-069 ◽

2008 ◽

Vol 45 (1) ◽

pp. 45-58 ◽

Cited By ~ 52

Author(s):

Dimitrios Zekkos ◽

Jonathan D. Bray ◽

Michael F. Riemer

Keyword(s):

Shear Modulus ◽

Large Scale ◽

Dynamic Properties ◽

Small Strain ◽

Unit Weight ◽

Material Damping ◽

Confining Stress ◽

Small Strain Shear Modulus ◽

Waste Composition ◽

Modulus Reduction

Representative dynamic properties of municipal solid waste (MSW) are required to perform reliable seismic analyses of MSW landfills. A comprehensive large-scale cyclic triaxial laboratory testing program was performed on MSW retrieved from a landfill in the San Francisco Bay area to evaluate the small-strain shear modulus, and strain-dependent normalized shear modulus reduction and material damping ratio relationships of MSW. The effects of waste composition, confining stress, unit weight, time under confinement, and loading frequency on these dynamic properties were evaluated. The small-strain shear modulus depends primarily on waste composition, confining stress, unit weight, and time under confinement. The normalized shear modulus reduction and material damping curves for MSW depend on waste composition and confining stress. Based on the results of this study and a review of literature, strain-dependent shear modulus reduction and material damping relationships are recommended for use in landfill design.

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

Materials ◽

10.3390/ma14112743 ◽

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.

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Elastic Stiffness of Volcanic Sand through Resonant Column Tests

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.775.292 ◽

2015 ◽

Vol 775 ◽

pp. 292-297

Author(s):

Kostas Senetakis ◽

Anastasios Anastasiadis

Keyword(s):

Dynamic Properties ◽

Experimental Testing ◽

Elastic Stiffness ◽

Laboratory Method ◽

Granular Soils ◽

Resonant Column ◽

Torsional Mode ◽

Resonant Column Test ◽

Basic Features ◽

Low Amplitude

The resonant column method is established as a standard laboratory method for the study of the elastic properties of soils. The study presents low-amplitude resonant column test results on volcanic sands with intra-particle voids. The experiments were performed on dry samples prepared at variable relative densities and tested in torsional mode of vibration. In the first part of the article, the important factors that control the elastic stiffness of uncemented sands are described shortly and recent findings on granular soils dynamic properties are presented briefly. The second part describes the basic features of the resonant column used in the investigation and the materials of the study and in the third part representative results of an extensive experimental testing program on volcanic granular soils are presented and discussed with a focus on comparisons between the elastic stiffness of volcanic and quartz granular soils. The importance of the effect of the presence of intra-particle voids within the particle mass of the volcanic soils is emphasized, which in turn affects markedly the global void ratio of the samples.

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Nonlinear Dynamic Properties of the Pancreas and Liver

IFAC Proceedings Volumes ◽

10.1016/s1474-6670(17)68076-5 ◽

1973 ◽

Vol 6 (4) ◽

pp. 503-508

Author(s):

Richard N. Bergman ◽

Richard J. Bucolo

Keyword(s):

Nonlinear Dynamic ◽

Dynamic Properties ◽

Nonlinear Dynamic Properties

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Effect of damage on nonlinear dynamic properties of viscoelastic rectangular plates

Applied Mathematics and Mechanics ◽

10.1007/bf02440082 ◽

2005 ◽

Vol 26 (3) ◽

pp. 319-326 ◽

Cited By ~ 5

Author(s):

Zheng Yu-fang ◽

Fu Yi-ming

Keyword(s):

Nonlinear Dynamic ◽

Dynamic Properties ◽

Rectangular Plates ◽

Nonlinear Dynamic Properties

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

Sustainability ◽

10.3390/su12041616 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1616 ◽

Cited By ~ 3

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.

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Measurement of small-strain shear modulus Gmax of dry and saturated sands by bender element, resonant column, and torsional shear tests

Canadian Geotechnical Journal ◽

10.1139/t08-069 ◽

2008 ◽

Vol 45 (10) ◽

pp. 1426-1438 ◽

Cited By ~ 70

Author(s):

Jun-Ung Youn ◽

Yun-Wook Choo ◽

Dong-Soo Kim

Keyword(s):

Shear Modulus ◽

Shear Wave ◽

Shear Wave Velocity ◽

Small Strain ◽

Resonant Column ◽

Test Results ◽

Bender Element ◽

Small Strain Shear Modulus ◽

Torsional Shear ◽

Saturated Sands

The bender element method is an experimental technique used to determine the small-strain shear modulus (Gmax) of a soil by measuring the velocity of shear wave propagation through a sample. Bender elements have been applied as versatile transducers to measure the Gmax of wet and dry soils in various laboratory apparatuses. However, certain aspects of the bender element method have yet to be clearly specified because of uncertainties in determining travel time. In this paper, the bender element (BE), resonant column (RC), and torsional shear (TS) tests were performed on the same specimens using the modified Stokoe-type RC and TS testing equipment. Two clean sands, Toyoura and silica sands, were tested at various densities and mean effective stresses under dry and saturated conditions. Based on the test results, methods of determining travel time in BE tests were evaluated by comparing the results of RC, TS, and BE tests. Also, methods to evaluate Gmax of saturated sands from the shear-wave velocity (Vs) obtained by RC and BE tests were investigated by comparing the three sets of test results. Biot’s theory on frequency dependence of shear-wave velocity was adopted to consider dispersion of a shear wave in saturated conditions. The results of this study suggest that the total mass density, which is commonly used to convert Gmax from the measured Vs in saturated soils, should not be used to convert Vs to Gmax when the frequency of excitation is 10% greater than the characteristic frequency (fc) of the soil.

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Dynamic Properties of Clean Sand Modified with Granulated Rubber

Advances in Civil Engineering ◽

10.1155/2018/5209494 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 7

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.

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