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 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 Characterization of the High Swelling Green Clay in the Vicinity of Amman Area

2021 ◽  
Vol 15 (1) ◽  
pp. 360-369
Author(s):  
Monther Abdel Hadi ◽  
Ibrahim Khliefat ◽  
Nafeth Abdelhadi ◽  
Nidhal Saada
Keyword(s):  
Moisture Content ◽  
Clay Mineral ◽  
Initial Moisture Content ◽  
Swelling Pressure ◽  
Liquid Limit ◽  
Engineering Properties ◽  
Dry Density ◽  
Initial Water Content ◽  
Foundation Design ◽  
Green Clay

Introduction: Jordan is awarded huge areas in the north and western part of the country in which brown and green clay is dominant. This research focuses on the problems and behaviour of the green clay only. The main problem of the green clay is its high swelling pressure which is the main cause of excessive settlement and wall cracks in buildings, especially during the wet season. Methods: This study aims to investigate the engineering properties and behaviour of the green clay deposits in the Amman area, which will serve as a guide for both geotechnical and structural engineers when preparing the foundation design. Results: Based on the consolidation test, the investigated green clay showed high swelling pressure of 3.11 kg/cm2, liquid limit (LL) of 73%, plasticity index (PI) of 40%, the shrinkage limit (SL) of 12%, and liquidity index (LI) of 0.125. The moisture content at saturation is 35.14%, while the natural moisture content is 28%, dry density is 1407 kg/m3, cohesion (C) is 0.20 kg/cm2 and unconfined compressive strength is 1.05 kg/cm2. The XRD results of the clay size fraction have confirmed the presence of the expansive clay mineral smectite as the essential clay mineral together with kaolinite. Results provide a general understanding of the behaviour and properties of the green clay, and the regression analysis showed good correlations between the liquid limit and initial moisture content with the compression index and also between the initial void ratios with the swelling index. Conclusion: Changes in the volume are due to the unsaturation level of clay when provided with initial water content.

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 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  .  

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 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 Initial Moisture Content of Corncobs Plays an Important Role in Maintaining its Quality during Storage

2018 ◽  
Vol 38 (2) ◽  
pp. 167
Author(s):  
Lince Mukkun ◽  
Herianus J.D. Lalel ◽  
Yuliana Tandirubak
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Insect Pests ◽  
Initial Moisture Content ◽  
High Water ◽  
High Water Content ◽  
Initial Water Content ◽  
Initial Water ◽  
Plant Materials ◽  
Randomized Design

Maize is one of the important staple foods for people in Timor, East Nusa Tenggara Province, Indonesia. Subsistent farmers store the maize for their own consumption until the next harvest season, for seed and feed.  However, high initial water content of the kernel due to improper drying prior storage initiate serious damage and losses during the maize storage.  High water content promotes the growth of fungi and insects, and increase respiration rate, resulting in rapid deterioration of maize. The purpose of this study was to determine the initial moisture content that might minimize damage and losses of maize in the farmers’ storage, and to study the effects of some plant materials that are used to smoke corns before storage. The experiment was initiated by sun-drying the harvested corncobs for 0, 2, 4, 6, 8, and 10 days (6 hours a day). This experiment was designed using Completely Randomized Design with 6 treatments and 3 replications. Dried corncobs were stored in the farmer’s storage for 4 months. The effects of maize kernels’ initial water content on the development of water content in kernels; the percentage of damaged kernels; and the species of pathogen and insects were investigated during storage with 2-week intervals.  The results demonstrated that drying the corncobs prior storage for 10 days, resulting in 12.96% of water content, significantly decreased the percentage of seed damage to 6.5%, as compared to without drying process which resulted  in 63%.  Aspergillus flavus, Fusarium sp., and Penicillium sp were found to be the main pathogen during storage.  There are no insect pests found during the storage. 

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.

Prediction Study of Capillary Rise Height on Unsaturated Soil

2013 ◽  
Vol 860-863 ◽  
pp. 1260-1264 ◽  
Author(s):  
Nian Qin Wang ◽  
Qing Tao Wang ◽  
Xiao Ling Liu ◽  
Qi Pang
Keyword(s):  
Moisture Content ◽  
Unsaturated Soil ◽  
Vertical Section ◽  
Capillary Rise ◽  
Initial Moisture Content ◽  
Absorption Capacity ◽  
Initial Water Content ◽  
Initial Water ◽  
The Difference ◽  
Rise Height

Based on the understanding of diseases of building’s foundation and manmade slope caused by water capillary rise, this thesis carried out a large number of laboratory tests by selfdeveloped absorption permeameter for unsaturated soil, in order to explore the capillary transport law of unsaturated soil. The thesis obtains some valuable results and conclusions: The moisture content shows minishing trend as the seepage fronts increasing, and reflects the gravitational potential of normal relations with the capillary action; (2) the water seepage frontal Hω% relation curve has no obvious inflection point, but the initial water content has an certain influence on the capillary moisture content distribution, the moisture content uses the initial moisture content of 12.5%, 9.8%, 8.0% and5.3% for testing showed an increasing trend at 4 cm and 16 cm sections, and the moisture content at the same section increased with the initial moisture content increasing, this reflects the rule that the smaller the moisture content is, the greater the matric potential, the water absorption capacity becomes stronger. (3)The moisture content difference between 4 cm and 16 cm of the initial moisture content is 12.5%, 9.8%, 8.0% and 9.8% is 1.48 %, 1.5 %, 1.7 % and 2.2 %, indicating that the smaller the initial moisture content is, the difference at the vertical section is greater. Finally, based on the relationship of Hω% curve, the thesis establishes the grey correlation prediction model, and forecasts the maximum capillary height of Lishi loess is 182cm.

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