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.

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.

Research on the Swelling Characteristics of Expansive Soil

2011 ◽  
Vol 250-253 ◽  
pp. 1761-1764
Author(s):  
Wei Fu ◽  
Wan Ping Wu ◽  
Sha Wu ◽  
Bin He ◽  
Yan Bin Ruan
Keyword(s):  
Initial Conditions ◽  
Three Dimensional ◽  
Expansive Soil ◽  
Quantitative Relationship ◽  
Dry Density ◽  
Time Interval ◽  
Initial Water Content ◽  
Initial Water ◽  
Overburden Pressure ◽  
Swelling Characteristics

Swelling tests of remolded expansive soil with water immersing are carried out by use of the simple consolidometers. The swelling characteristics of the expansive soil under the different initial conditions are studied. The Dose Response model is used to fit the rules of swelling time interval for expansive soil with water immersing. The quantitative relationship among the swelling and initial overburden pressure, initial water content and initial dry density is attained by use of the three dimensional regression analyses. The important index obtained could be provided to the engineering design, construction and stability evaluation of expansive soil slopes.

scholarly journals Pengaruh Kadar Air Awal Dan Surcharge Pressure Pada Uji Karakteristik Pengembangan Tanah Ekspansif

2017 ◽  
Vol 23 (2) ◽  
pp. 124
Author(s):  
Wilis Diana ◽  
Edi Hartono ◽  
Anita Widianti
Keyword(s):  
Water Content ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Dry Density ◽  
Initial Water Content ◽  
Expansive Clay ◽  
Initial Water ◽  
Swelling Properties ◽  
Swell Percent ◽  
Swell Pressure

Expansive soils experience volumetric changes due to water content changes. These volumetric changes cause swell and shrink movement in soils, which in turn will inflict severe damage to structures built above them. A Proper understanding of how the expansive soil behaves during the wetting/drying process is essential for assessing the mitigation action of expansive soil hazard and design suitable foundation. The structures that build above expansive soil bed are susceptible to heave and to withstand swell pressure, thus the swell pressure must be considered in the design. This study focuses on swelling properties of two expansive clay from Ngawi, East Java and Wates, Yogyakarta. Laboratory test on disturbed samples is used to identified and to measured swelling properties. A series of swelling test was performed under constant soil dry density. The influence of initial water content and surcharge pressure on swelling properties (i.e swell percent and swell pressure) of compacted samples were investigated. The swelling properties test used ASTM standard 4546-03 method B. It was found that the lower initial water content the higher the swell percent, but the swell pressure seems not to be affected by initial water content. At the same initial water content, swell percent decrease with the increase of surcharge pressure, but swell pressure remains unchanged.

scholarly journals Factors Affecting the Swelling-Compression Characteristics of Clays in Yichang, China

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Changxi Huang ◽  
Xinghua Wang ◽  
Hao Zhou ◽  
Yan Liang
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Stress Path ◽  
Dry Density ◽  
Initial Water Content ◽  
Initial Water ◽  
Swelling Properties ◽  
Vertical Loading

Expansive soil has been studied for eighty decades because it is prone to cause geotechnical engineering accidents. The results of the moisture content effects on the expansive pressure were not consistent in the literatures. In this paper, swelling deformation and pressure tests were conducted to clarify the effects of the initial water content on the swelling properties. The relation of expansive stress and initial moisture content was accurately described with a Gaussian distribution, unlike in the previously published studies. These results could be explained by the change in the microstructure with diverse moisture contents. In addition, dry density and vertical stress influences on expansive properties were analysed. With an increase in the vertical loading, the soil samples first expanded, and then the samples with a lower dry density collapsed; however, the samples with a higher dry density did not collapse, even under a considerable vertical loading. Furthermore, the relation between stress path and expansive pressure was examined. It was observed that the swelling pressures obtained from the constant volume tests were greater than the results from the swell under load tests. The relationship between the swelling pressure and swelling strain was also analysed.

scholarly journals Factors affecting the swelling pressure for Jerash expansive soil

2021 ◽  
Vol 3 (2) ◽  
pp. 44-51
Author(s):  
Talal Masoud ◽  
Abdulrazzaq Jawish Alkherret
Keyword(s):  
Water Content ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Dry Density ◽  
Initial Water Content ◽  
Content Increase ◽  
Initial Water ◽  
Factors Affecting ◽  
Water Content Increase

  In this study for factors effecting the swelling pressure of jerash expansive soils were investigated in this study, effect of initial dry density and effect of initial water content on the jerash expansive soil were investigated.It show that as the initial dry density decrease from 1.85 gm/cm3  to1.25 gm/cm3 , the swelling pressure also decrease are from 3.1  to 0.25gm/cm2   also it show that as the initial water content increase from 0%to 15% , the swelling pressure of jerash expansive soil decrease from 2.65 gm/cm2  to 1.35 gm/cm2  .  

Influence of initial water content on unsaturated shear strength of compacted GaoMiaoZi (GMZ) bentonite

2021 ◽  
Vol 58 (1) ◽  
pp. 142-146
Author(s):  
N.F. Zhao ◽  
W.M. Ye ◽  
Q. Wang ◽  
B. Chen ◽  
Y.-J. Cui
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Critical State ◽  
Initial Water Content ◽  
Gmz Bentonite ◽  
Test Results ◽  
Loading Test ◽  
Initial Water ◽  
State Stress ◽  
Water Contents

This paper presents an experimental study on the influence of initial water content on unsaturated shear strength of compacted bentonite. Isotropic loading and triaxial shear tests were conducted on compacted GaoMiaoZi (GMZ) bentonite specimens with different initial water contents. Isotropic loading test and triaxial shear test results show that the compression index increases and yield stress decreases with increasing water content, while the swelling index stays constant. For normally consolidated and lightly overconsolidated bentonite, unsaturated shear strength can be described by the critical state line. For highly overconsolidated bentonite, unsaturated shear strength can be described by the Hvorslev surface. The critical state line and Hvorslev surface are found to be linear for the specimens with different water contents. The critical state stress ratio and the Hvorslev surface parameters are found to decrease with an increase in water content of the bentonite studied.

Study on Expansion and Deformation Characteristics of Expansive Soil in Yunnan Province

2012 ◽  
Vol 204-208 ◽  
pp. 37-40
Author(s):  
Ying Xin Zhou ◽  
Chuan Tang ◽  
Ming Zhang ◽  
Rui Qiang Yue ◽  
Yong Ma ◽  
...  
Keyword(s):  
Initial Conditions ◽  
Three Dimensional ◽  
Expansive Soil ◽  
Quantitative Relationship ◽  
Dry Density ◽  
Time Interval ◽  
Initial Water Content ◽  
Initial Water ◽  
Overburden Pressure ◽  
Swelling Characteristics

Swelling tests of remolded expansive soil with water immersing are carried out by use of the simple consolidometers. The swelling characteristics of the expansive soil under the different initial conditions are studied. The Dose Response model is used to fit the rules of swelling time interval for expansive soil with water immersing. The quantitative relationship among the swelling and initial overburden pressure, initial water content and initial dry density is attained by use of the three dimensional regression analyses. The important index obtained could be provided to the engineering design, construction and stability evaluation of expansive soil slopes.

scholarly journals Experimental Study on Relationship between Free Load Swelling Rate and Water Content of Medium Expansive Soil

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Cheng Song ◽  
Ligong Yang ◽  
Wei Xia ◽  
Wendong Ji ◽  
Yuting Zhang
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Moisture Absorption ◽  
Initial Moisture Content ◽  
Expansive Soil ◽  
Experimental Tests ◽  
Expansion Rate ◽  
Dry Density ◽  
Initial Water Content ◽  
Initial Water

Expansive soil has the property of water swelling, which is related not only to the hydrophilic mineral composition of soil particles and the microstructure of soil, but also to the initial moisture content, dry density, and overburden condition of soil. Based on the typical expansive soil in a certain area, the samples were sampled and remodeled at the site. Extensive experimental tests were conducted to investigate the relationship between the hygroscopic expansion rate and the water content of the expansive soil under different initial moisture content, dry density, and free load. The results showed that, under the condition of natural initial water content and dry density, although the hygroscopic expansion rate of the medium expansive soil was nonlinear with the subsequent water content, in the range of large water content (within about 50%), the expansive soil swelled linearly. There was a linear relationship between the rate and the water content. With the increase of the initial water content, the hygroscopic expansion rate and expansion rate of the expansive soil decreased. With the increase of the dry density, the hygroscopic expansion rate and the expansion rate of the expansive soil increased. The water absorption performance did not decrease, and the soil continued to maintain the previous moisture absorption rate and expansion rate after the soil reached saturation, while after the water content reached 1.5∼2.0 times the saturated water content, the soil moisture absorption expansion rate gradually decreased until it finally stabilized. The slope k of the expansion rate increased with the initial dry density and decreased with the initial moisture content. As dry density was increased, the slope k was increased at an increased rate. Moreover, as the initial moisture content was decreased, the slope k was increased at an increased rate.

scholarly journals Mechanical Properties of Tailings Sample with Different Moisture Contents under Dry and Wet Cycles

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Ling-ling Wu ◽  
Yao-hui Guo ◽  
Kai-wen Tong ◽  
Lin Hu ◽  
Qing Yu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Content ◽  
Moisture Absorption ◽  
Water Pressure ◽  
Hunan Province ◽  
Dry Density ◽  
Initial Water Content ◽  
Sand Sample ◽  
Stress Strain ◽  
Tailings Sand

Due to precipitation infiltration, evaporation of water, and rising and falling of the wetting line, the tailings are in a cyclical moisture absorption-dehumidification state for a long time. The mechanism of change of physical and mechanical properties of tailings during the dry and wet cycle is related to the safe operation of the entire tailings dam. In order to explore the variation of the mechanical behavior of tailings in a tailings pond in Hunan Province with the number of dry and wet cycles under different initial water content conditions, the tailings sand samples with moisture content of 6.10%, 10.40%, 14.00%, 18.20%, and 21.00% were subjected to 0 to 6 times of moisture absorption and desorption cycles at natural dry density, and then, the stress-strain relationship curves, pore water pressure, failure mode, and shear dilatancy of these samples were tested by triaxial consolidation undrained shear test. The test results showed that when the number of moisture absorption and desorption cycles increases, the strength of the tailings sand sample was weakened, and the strength tended to be stable after 3∼5 cycles. In addition, the stress-strain curve of the sample with lower water content dropped sharply. However, the pore pressure of tailings sand samples with different water contents under different wet and dry cycles all showed a phenomenon of increasing first and then decreasing in general.

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