scholarly journals Triaxial Wetting Test on Rockfill Materials under Stress Combination Conditions of Spherical Stress p and Deviatoric Stress q

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Yan-yi Zhang ◽  
Ze-ping Xu ◽  
Gang Deng ◽  
Yan-feng Wen ◽  
Shu Yu ◽  
...  
Keyword(s):  
Shear Strain ◽  
Power Function ◽  
Volumetric Strain ◽  
Deviatoric Stress ◽  
Dry Density ◽  
Initial Water Content ◽  
Test Results ◽  
Rockfill Materials ◽  
Function Relationship ◽  
Wetting Deformation

A GCTS medium-sized triaxial apparatus is used to conduct a single-line method wetting test on three kinds of rockfill materials of different mother rocks such as mixture of sandstone and slate, and dolomite and granite, and the test stress conditions is the combination of spherical stress p and deviatoric stress q. The test results show that (1) for wetting shear strain, the effects of spherical stress p and deviatoric stress q are equivalent, and wetting shear strain and deviatoric stress q show the power function relationship preferably. (2) For wetting volumetric strain, the effect of deviatoric stress q can be neglected because it is extremely insignificant, and spherical stress p is the main influencing factor and shows the power function relationship preferably. (3) The wetting strains decrease significantly with the increase in initial water content and sample density generally, but the excessively high dry density will increase the wetting deformation. Also, the wetting strains will decrease with the increase in the saturated uniaxial compressive strength and average softening coefficient of the mother rock. Based on the test results, a wetting strain model is proposed for rockfill materials. The verification results indicate that the model satisfactorily reflects the development law of wetting deformation.

scholarly journals RESEARCH ON MODEL FITTING AND STRENGTH CHARACTERISTICS OF CRITICAL STATE FOR EXPANSIVE SOIL

2013 ◽  
Vol 19 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Zhiqing Li ◽  
Chuan Tang ◽  
Ruilin Hu ◽  
Yingxin Zhou
Keyword(s):  
Critical State ◽  
Model Fitting ◽  
Expansive Soil ◽  
Dry Density ◽  
Initial Water Content ◽  
Test Results ◽  
Stress Strain ◽  
Initial Water ◽  
Curve Model ◽  
Shearing Strength

According to Mengzi expansive soil, consolidated drained tests and undrained tests are carried on under saturated and remoulded conditions. The stress-strain characteristics of saturated soil are researched systematically under different confining pressure, initial dry density, initial water content, shearing rate and drainage condition. The inherent unity of diversity of shearing strength for the same samples measured by different experimental methods is indicated according to the normalization of critical state test results. And the failure lines in p ‘- q - ν space of remoulded saturated expansive soil under consolidated drained and undrained conditions are attained. The hyperbolic curve model can fit well the weak hardening stress-strain curves and the exponential curve model can fit the weak softening stress-strain curves. The test results can provide technical parameters and theoretical help for shearing strength variation of slope during rainfall and strength state of soil structure in normal water level.

Experimental Study on Slaking Deformation of the Remolded Laterite

2014 ◽  
Vol 584-586 ◽  
pp. 1192-1196
Author(s):  
Xiao Wen Liu ◽  
Xiao Yan Chen
Keyword(s):  
Experimental Study ◽  
Stress State ◽  
Axial Strain ◽  
Volumetric Strain ◽  
Reference Value ◽  
Test Results ◽  
Stress Strain ◽  
Modulus Of Deformation ◽  
Logarithmic Relationship ◽  
Wetting Deformation

Through lots of triaxial and a single-line wetting path experiments for slaking deformation of the remolded laterite , behaviors of stress-strain and volumetric strain-axial strain are studied at different level values of wetting stress.The test results indicate that the modulus of deformation and the strength of samples are reduced by wetting, that the value of wetting deformation is relation to the stress state and that the logarithmic relationship between wetting axial strain of the type of laterite and wetting stress levels meets . The test results obtained have an important reference value for actual projects in Jiangxi laterite area.

Experimental study on swelling characteristics of compacted bentonite

1994 ◽  
Vol 31 (4) ◽  
pp. 478-490 ◽  
Author(s):  
Hideo Komine ◽  
Nobuhide Ogata
Keyword(s):  
Water Content ◽  
Nuclear Waste ◽  
Volumetric Strain ◽  
Swelling Pressure ◽  
Dry Density ◽  
Initial Water Content ◽  
Initial Water ◽  
Compacted Bentonite ◽  
Swelling Characteristics ◽  
High Level

Compacted bentonites are attracting greater attention as back-filling (buffer) materials for repositories of high-level nuclear waste. However, since there are few studies about the swelling characteristics of compacted bentonites, it is first necessary to clarify the fundamental swelling characteristics in detail. For this purpose, various laboratory tests on the swelling deformation and swelling pressure of compacted bentonites were performed and the results analyzed. The following conclusions were drawn from the study. (i) The curve of swelling deformation versus time is strongly dependent on the initial dry density, vertical pressure, and initial water content. The maximum swelling deformation, however, is almost independent of initial water content, and the maximum swelling deformation increases in proportion to the initial dry density, (ii) The maximum swelling pressure increases exponentially with increasing initial dry density, whereas the maximum swelling pressure is almost independent of initial water content. (iii) The swelling mechanism of compacted bentonite was considered on the basis of the swelling behavior of swelling clay particles such as montmorillonite. Furthermore, a model of the swelling characteristics and a new parameter (swelling volumetric strain of montmorillonite), which were able to evaluate the swelling characteristics of compacted bentonite, were proposed. Key words : bentonite, laboratory test, nuclear waste disposal, swelling deformation, swelling pressure.

scholarly journals Effects of fines content on liquefaction strength and dynamic settlement of reclaimed soil

2002 ◽  
Vol 39 (1) ◽  
pp. 254-265 ◽  
Author(s):  
Lien-Kwei Chien ◽  
Yan-Nam Oh ◽  
Chih-Hsin Chang
Keyword(s):  
Relative Density ◽  
Land Reclamation ◽  
Volumetric Strain ◽  
Soil Liquefaction ◽  
Dry Density ◽  
Test Results ◽  
Liquefaction Resistance ◽  
Fines Content ◽  
Reclaimed Soil ◽  
Dynamic Settlement

In this study, the reclaimed soils in the Yunlin area of west Taiwan are adopted as test samples. The specimens were prepared by moist tamping at different relative densities and fines contents. Triaxial liquefaction tests were performed to evaluate the liquefaction strength and liquefaction-induced settlement. The test results show that the liquefaction strength of reclaimed soil increases as the relative density increases. In addition, under constant relative density, the liquefaction strength decreases as the fines content increases. Based on the test results and one-dimensional consolidation theory, the volumetric strain and settlement can be evaluated by dry density and fines content of the reclaimed soil. The results show that the settlement ratio decreases as the relative density increases. The figures and results can be references for the evaluation of liquefaction strength and liquefaction-induced settlement. The results are useful for liquefaction strength and settlement analysis for planning, design, and related research on land reclamation engineering.Key words: reclaimed soil, liquefaction resistance, fines content, settlement.

Research on Strength Characteristics of Expansive Soil

2011 ◽  
Vol 109 ◽  
pp. 96-99
Author(s):  
Qian Li ◽  
Le Fu
Keyword(s):  
Critical State ◽  
Expansive Soil ◽  
Confining Pressure ◽  
Experimental Methods ◽  
Dry Density ◽  
Initial Water Content ◽  
Test Results ◽  
Initial Water ◽  
State Test ◽  
Shearing Strength

According to expansive soil, consolidated drained tests and undrained tests are carried on under saturated and remoulded conditions. The stress-strain characteristics of saturated soil are researched systematically under different confining pressure, initial dry density, initial water content, shearing rate and drainage condition. The inherent unity of diversity of shearing strength for the same samples measured by different experimental methods is indicated according to the normalization of critical state test results.

scholarly journals Application of Philip infiltration model to film hole irrigation

2018 ◽  
Vol 19 (3) ◽  
pp. 978-985 ◽  
Author(s):  
Yanwei Fan ◽  
Jiaguo Gong ◽  
Ying Wang ◽  
Xiaoxia Shao ◽  
Tong Zhao
Keyword(s):  
Influencing Factors ◽  
Power Function ◽  
Water Depth ◽  
Soil Texture ◽  
Hole Diameter ◽  
Model Parameters ◽  
Initial Water Content ◽  
Infiltration Model ◽  
Cumulative Infiltration ◽  
Function Relationship

Abstract Numerical simulations were carried out with HYDRUS-2D to investigate the influence of soil texture, initial water content, film hole diameter and water depth on cumulative infiltration from a film hole. Soil texture, film hole diameter and water depth are the dominant influencing factors. Philip infiltration model was used to fit the simulated results of the dominant influencing factors. For the same soil, the sorptivity (s) is a power function relationship with film hole diameter, while the steady infiltration rate (a) is a power function relationship with film hole diameter and water depth. On that basis, the calculation formulas for predicting s and a were established, and a simplified film hole infiltration model including the film hole diameter and water depth was proposed. The effectiveness of the model was verified by laboratory experiments and literature data. The predicted values of the model were in good agreement with the experimental observations. The model parameters can be determined only by a set of film hole infiltration experiment, which simplifies the experimental design and can be used as a tool for irrigation engineers or farmers to estimate cumulative infiltration.

An Analytical Elasto-Plastic Analysis for Stability of Axisymmetric Wellbore

2014 ◽  
Author(s):  
Shengli Chen ◽  
Younane Abousleiman ◽  
Hazim Abass
Keyword(s):  
Shear Strain ◽  
Triaxial Compression ◽  
Volumetric Strain ◽  
Soft Rock ◽  
Stress Path ◽  
Test Results ◽  
Wellbore Instability ◽  
Rock Formations ◽  
Plastic Shear Strain ◽  
Collapse Failure

In this paper, a general shear strain hardening and softening Drucker-Prager model based on the existing triaxial compression test results has been introduced to model the rock behaviour which captures well the mechanical characteristic of typical soft rock formations. This elastoplastic model is then adopted to develop a rigorous analytical solution for the drained wellbore drilling problem subjected to in-plane isotropic stress field, and to simulate the borehole collapse failure. It is found that the wellbore boundary value problem can be reduced to solving a system of first order ordinary differential equations in the plastic zone, with the radial, tangential, and vertical stresses as well as the volumetric strain and plastic shear strain being the five basic unknowns. The illustration numerical example shows the distributions of stress components and volumetric strain around the borehole, in addition to the evolving plastic deviatoic strain and stress path for a rock point at the borehole surface due to the wellbore drilling. The critical mud pressures necessary to prevent borehole collapse, predicted by the elastoplastic analysis based on different wellbore instability criteria, are compared with the value corresponding to the elastic theory, which are found to be considerably lower.

Experimental Investigation for Horizontal Ultimate Bearing Capacity and Target Ductility Factor Improvement Results of the RC Column Reinforced by AFL with Damages

2014 ◽  
Vol 488-489 ◽  
pp. 497-500
Author(s):  
You Lin Zou ◽  
Pei Yan Huang
Keyword(s):  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
Test Results ◽  
Rc Columns ◽  
Static Test ◽  
Rc Column ◽  
Ductility Factor ◽  
Secant Stiffness ◽  
Function Relationship ◽  
Reversed Cyclic

Deem test results from the low reversed cyclic loading quasi-static test with 2 RC columns as the basic information of secant stiffness damage of the reference column and take use of the TMS instrument in the test to artificially make the damage percentage of secant stiffness of the RC column as 33%, 50% and 66%, 6 damaged columns in total; reinforce the 6 damaged columns and 2 undamaged ones under the same conditions with AFL, through quasi-static contrast test. Test results show that it is able to effectively boost horizontal ultimate bearing capacity and ductility deformability of the RC columns with AFL for reinforcement; besides, there is a linear function relationship between horizontal ultimate bearing capacity, target ductility factor, and damage percentage of secant stiffness.

The Analysis of Stress Distribution of Hammer Bottom during Dynamic Compaction on Sandy Soil Foundation

2011 ◽  
Vol 250-253 ◽  
pp. 1460-1463
Author(s):  
Jian Qi Wu ◽  
Jian Hong Deng ◽  
Xiao Ping Wang
Keyword(s):  
Comparative Analysis ◽  
Stress Distribution ◽  
Sandy Soil ◽  
Field Monitoring ◽  
Dynamic Compaction ◽  
Dry Density ◽  
Test Results ◽  
Red Sandstone ◽  
Soil Foundation

Obtained stress distribution of hammer bottom according to the analysis of horizontal and vertical red sandstone fill dry density of the hammer bottom after dynamic compaction; affirmed the stress distribution situation of the hammer bottom through comparative analysis of the test results by laboratory and field monitoring.

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.

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