scholarly journals Evaluation of Compressive Strength and Stiffness of Grouted Soils by Using Elastic Waves

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
In-Mo Lee ◽  
Jong-Sun Kim ◽  
Hyung-Koo Yoon ◽  
Jong-Sub Lee
Keyword(s):  
Elastic Wave ◽  
Elastic Waves ◽  
Large Strain ◽  
Small Strain ◽  
Test Results ◽  
Wave Velocities ◽  
Strength Tests ◽  
Soil Media ◽  
Strength And Stiffness ◽  
Particulate Soil

Cement grouted soils, which consist of particulate soil media and cementation agents, have been widely used for the improvement of the strength and stiffness of weak ground and for the prevention of the leakage of ground water. The strength, elastic modulus, and Poisson’s ratio of grouted soils have been determined by classical destructive methods. However, the performance of grouted soils depends on several parameters such as the distribution of particle size of the particulate soil media, grouting pressure, curing time, curing method, and ground water flow. In this study, elastic wave velocities are used to estimate the strength and elastic modulus, which are generally obtained by classical strength tests. Nondestructive tests by using elastic waves at small strain are conducted before and during classical strength tests at large strain. The test results are compared to identify correlations between the elastic wave velocity measured at small strain and strength and stiffness measured at large strain. The test results show that the strength and stiffness have exponential relationship with elastic wave velocities. This study demonstrates that nondestructive methods by using elastic waves may significantly improve the strength and stiffness evaluation processes of grouted soils.

EVALUATION OF THE TIME-DEPENDENT CHARACTERISTICS OF GROUTED SAND USING AN ELASTIC WAVE

2008 ◽  
Vol 22 (11) ◽  
pp. 899-904 ◽  
Author(s):  
JOOWON KIM ◽  
KI-IL SONG ◽  
GYE-CHUN CHO ◽  
SEOK-WON LEE
Keyword(s):  
Numerical Modeling ◽  
Elastic Wave ◽  
Elastic Waves ◽  
Experimental Tests ◽  
Time Dependent ◽  
Soft Ground ◽  
Large Section ◽  
Wave Velocities ◽  
Dependent Behavior ◽  
Strength And Stiffness

For a better evaluation of a grouted zone during and after tunnel construction involving weak soil layers, it is necessary to estimate the characteristics of grouted zone effectively. This study suggests a method that can be used for characterizing the time-dependent behavior of pre-reinforced zones around a large section of tunnel in soft ground using elastic waves. Experimental tests were performed to characterize the time-dependent behavior of the pre-reinforced zone. Experimental results show that shear strengths as well as elastic wave velocities increase with the curing time. Thus, shear strength or strength parameters can be uniquely correlated to elastic wave velocities. It is possible to characterize grouted soils around tunnel using elastic waves. Time-dependent strength and stiffness parameters in the experimental tests were applied in a numerical modeling of a large-section tunnel in soft ground, taking into account its construction sequence. According to the results of the numerical modeling, displacement results for fewer than 2~3 days of constant time boundary conditions are nearly identical to the analysis results of the time-dependent condition. The proposed analysis method, which combines experimental and numerical procedures while considering the time-dependent effect of the pre-reinforced zone on the tunnel behavior, will provide a reliable and practical design basis and a means of analysis for large-section tunnels in soft ground.

scholarly journals Effects of Crumb Rubber on Compressive Strength of Cement-Treated Soil

2015 ◽  
Vol 61 (4) ◽  
pp. 59-78 ◽  
Author(s):  
F. C. Wang ◽  
W. Song
Keyword(s):  
Compressive Strength ◽  
Cement Content ◽  
Rubber Particle ◽  
Crumb Rubber ◽  
Test Results ◽  
Rubber Content ◽  
Strength Tests ◽  
Strength And Stiffness ◽  
Cement Soil ◽  
Curing Age

A study was undertaken to investigate the effects of crumb rubber on the strength and mechanical behaviour of Rubberized cement soil (RCS). In the present investigation, 26 groups of soil samples were prepared at five different percentages of crumb rubber content, four different percentages of cement content and two different finenesses of crumb rubber particle. Compressive strength tests were carried out at the curing age of 7 days, 14 days, 28 days and 90 days. The test results indicated that the inclusion of crumb rubber within cement soil leads to a decrease in the compressive strength and stiffness and improves the cement soil’s brittle behaviour to a more ductile one. A reduction of up to 31% in the compressive strength happened in the 20% crumb content group. The compressive strength increases with the increase in the cement content. And the enlargement of cement content is more efficient at low cement content.

SEISMIC VELOCITY STUDY OF SYNTHETIC CORES

Geophysics ◽  
1957 ◽  
Vol 22 (4) ◽  
pp. 813-820 ◽  
Author(s):  
William O. Murphy ◽  
Joseph W. Berg ◽  
Kenneth L. Cook
Keyword(s):  
Elastic Wave ◽  
Elastic Waves ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Seismic Velocity ◽  
Pore Filling ◽  
The Core ◽  
Wave Velocities ◽  
Longitudinal Elastic Wave ◽  
Alcohol Benzene

The velocity of a longitudinal elastic wave through rock at room temperature and at atmospheric pressure depends upon the nature of the rock frame, the porosity of the rock, and the nature of the pore‐filling fluid. In the present investigation longitudinal elastic wave velocities were measured for sixty synthetic cores. The rock frame consisted of sorted quartz sand grains and cement, the percentage of cement varying from ten to fifty percent. The core porosities varied from 8.8 percent to 22 percent. The velocities were measured for dry air‐filled cores and for cores saturated with various liquids. These pore‐filling liquids were distilled water, ethyl alcohol, benzene, carbon tetrachloride, and chloroform. The measured velocities ranged from 2,360 feet per second to 14,710 feet per second. The wave velocity in liquid‐filled cores of 10 percent porosity was approximately twice the velocity for cores of 20 percent porosity, the same type of cement being used in both instances. For any given core, flooded with fluids of wave velocities ranging from 3,000 to 5,000 feet per second, the maximum observed variation in core velocity was around 20 percent. The experimental data fitted the empirical linear equation [Formula: see text] where [Formula: see text] of longitudinal elastic waves passing through the flooded core; [Formula: see text] of longitudinal elastic waves in passing through the saturating fluid. The constant k depends upon the porosity of the rock and the type of cement used. The constant, C, depends upon the nature of the rock frame.

TOTAL POROSITY AND MATRIX PARAMETERS OF CARBONATE ROCKS BASED ON THE ELASTIC WAVE VELOCITY AND DENSITY MEASUREMENTS

2018 ◽  
Vol 473 (473) ◽  
pp. 13-26
Author(s):  
Jadwiga JARZYNA ◽  
Edyta PUSKARCZYK ◽  
Ewa OGÓREK ◽  
Jacek MOTYKA
Keyword(s):  
Elastic Wave ◽  
Elastic Waves ◽  
Total Porosity ◽  
Elastic Wave Velocity ◽  
P Wave ◽  
Reservoir Properties ◽  
Rock Samples ◽  
Additional Information ◽  
Wave Velocities ◽  
Boundary Velocity

The purpose of the research was to find relationship between elastic waves velocities obtained from lab measurements and parameters from hydrogeological research. Measurements were conducted on 73 rock samples originating mostly from Jurassic limestone of the Olkusz area. Additional information about the rock samples was obtained when the elastic wave velocities were compared with reservoir parameters such as porosity, permeability and density. Plots of elastic waves velocities vs. porosity and bulk density vs. porosity gave information about the range of P wave velocities from the boundary velocity to the values when porosity is equal to zero. Matrix velocity and density values were introduced into the formulas used to calculate porosity. Anisotropy analysis was made on the basis of elastic wave velocities measured on cores cut in two perpendicular directions. This allowed for identification of fractures in rocks. Results showed that by comparing various petrophysical parameters it was possible to get better information about reservoir properties of aquifers.

Cementation and bond degradation of rubber–sand mixtures

2010 ◽  
Vol 47 (7) ◽  
pp. 763-774 ◽  
Author(s):  
Changho Lee ◽  
Q. Hung Truong ◽  
Jong-Sub Lee
Keyword(s):  
Elastic Wave ◽  
Rubber Particle ◽  
Small Strain ◽  
Vertical Stress ◽  
Body Waves ◽  
Interparticle Contact ◽  
Stress Strain ◽  
Vertical Loading ◽  
Wave Velocities ◽  
Bond Degradation

Cementation influences the mechanical behavior of soils. The effects of cementation and bond degradation are investigated for lightly cemented rigid sand and soft rubber particle mixtures subjected to vertical loading under the K0 condition. Cemented and uncemented specimens were prepared with various sand volume fractions. The propagation velocity of small strain body waves was measured by piezo materials, incorporated within an oedometer. Cemented specimens exhibited a bilinear behavior in the semi-log plot (vertical strain versus log of vertical stress). Vertical strains of a cemented specimen normalized by an uncemented specimen show that the stress–strain behavior is controlled by several different mechanisms and forces: capillary force, cementation bonds, and interparticle contact stresses after bond degradation. The elastic wave velocities dramatically increase due to cementation hardening under fixed vertical stress, and are constant after curing even though vertical stress increases. Additional loading of the vertical effective stress decreases the elastic wave velocities due to bond degradation. The shear wave velocity presents three behavior regions as a function of the sand fraction for both uncemented and cemented specimens: rubber-like, sand-like, and transition behaviors. The vertical stress–strain response and the elastic wave velocities can serve as indicators of cementation and bond degradation.

Study on the Dynamics Characteristics of Elastic Wave of Weathered Zone in Longmen Grottoes

2011 ◽  
Vol 105-107 ◽  
pp. 1509-1512
Author(s):  
Wu Xiu Ding ◽  
Hong Yi Wang
Keyword(s):  
Elastic Wave ◽  
Attenuation Coefficient ◽  
Wave Velocity ◽  
P Wave ◽  
Test Results ◽  
S Wave ◽  
Wave Velocities ◽  
Weathered Zone

Based on the test results, the wave velocity and the attenuation rule of elastic wave of weathered zone in Longmen Grottoes are studied. The wave velocity decreases with the increasing of the attenuation coefficient in a certain range. When wave velocity decreases to a certain value, there is not a relationship between wave velocity and attenuation coefficient. The attenuation coefficient thresholds of P-wave 0.01and S-wave 0.1 separate good rockmass quality from poor rockmass quality. The test results show that the elastic wave velocities of the surrounding rocks are generally high, which indicates that the rockmass skeleton is solid. But the rockmass anisotropy is obvious, which indicates that the structure planes are more developed. The results of the study are important for the protection of historical relics.

Study on the Characteristics of Elastic Wave Velocities of Rockmass under Different Test Methods

2012 ◽  
Vol 170-173 ◽  
pp. 449-452 ◽  
Author(s):  
Wu Xiu Ding ◽  
Hong Yi Wang ◽  
Bing Xie
Keyword(s):  
Elastic Wave ◽  
Influence Factors ◽  
Field Tests ◽  
Test Methods ◽  
Test Results ◽  
Penetration Test ◽  
Wave Velocities ◽  
Test Conditions ◽  
Study Results ◽  
Main Influence

There are many methods of testing elastic wave velocities of engineering rockmass such as the elastic wave penetration test between adits, elastic wave test on the adit wall and the borehole sonic method etc, but the test results vary with different test methods. It is important to understand and apply appropriately the test results. Based on the field tests, the characteristics of elastic wave velocities under different test methods are studied. The research indicates that the main influence factors of different test methods on wave velocities include the rockmass occurrence environments and the test conditions. For the elastic wave penetration test between adits, the rockmass occurrence environments are basically unchanged, and the influences of the test conditions are little, so the wave velocity obtained by this method is more scientific. The study results are important for the reasonable evaluation of engineering rockmass.

Sunlight exposure: the effects on the performance of paragliding fabric

2018 ◽  
Vol 69 (05) ◽  
pp. 381-389
Author(s):  
MENGÜÇ GAMZE SÜPÜREN ◽  
TEMEL EMRAH ◽  
BOZDOĞAN FARUK
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Air Permeability ◽  
Sunlight Exposure ◽  
Test Results ◽  
Coating Materials ◽  
Strength Tests ◽  
Before And After ◽  
The Relationship ◽  
Dark Blue

This study was designed to explore the relationship between sunlight exposure and the mechanical properties of paragliding fabrics which have different colors, densities, yarn counts, and coating materials. This study exposed 5 different colors of paragliding fabrics (red, turquoise, dark blue, orange, and white) to intense sunlight for 150 hours during the summer from 9:00 a.m. to 3:00 p.m. for 5 days a week for 5 weeks. Before and after the UV radiation aging process, the air permeability, tensile strength, tear strength, and bursting strength tests were performed. Test results were also evaluated using statistical methods. According to the results, the fading of the turquoise fabric was found to be the highest among the studied fabrics. It was determined that there is a significant decrease in the mechanical properties of the fabrics after sunlight exposure. After aging, the fabrics become considerably weaker in the case of mechanical properties due to the degradation in both the dyestuff and macromolecular structure of the fiber

Hysteresis loss of ultra-large off-the-road tire rubber compounds based on operating conditions at mine sites

2021 ◽  
pp. 095440702110155
Author(s):  
Shaosen Ma ◽  
Guangping Huang ◽  
Khaled Obaia ◽  
Soon Won Moon ◽  
Wei Victor Liu
Keyword(s):  
Large Strain ◽  
Tensile Tests ◽  
Operating Conditions ◽  
Hysteresis Loss ◽  
Strain Rates ◽  
Test Results ◽  
Tire Rubber ◽  
The Road ◽  
Rubber Compounds ◽  
Mine Sites

The objective of this study is to investigate the hysteresis loss of ultra-large off-the-road (OTR) tire rubber compounds based on typical operating conditions at mine sites. Cyclic tensile tests were conducted on tread and sidewall compounds at six strain levels ranging from 10% to 100%, eight strain rates from 10% to 500% s−1 and 14 rubber temperatures from −30°C to 100°C. The test results showed that a large strain level (e.g. 100%) increased the hysteresis loss of tire rubber compounds considerably. Hysteresis loss of tire rubber compounds increased with a rise of strain rates, and the increasing rates became greater at large strain levels (e.g. 100%). Moreover, a rise of rubber temperatures caused a decrease in hysteresis loss; however, the decrease became less significant when the rubber temperatures were above 10°C. Compared with tread compounds, sidewall compounds showed greater hysteresis loss values and more rapid increases in hysteresis loss with the rising strain rate.

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