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 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 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. 

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 Adjustment of mathematical models and quality of soybean grains in the drying with high temperatures

2016 ◽  
Vol 20 (4) ◽  
pp. 385-392 ◽  
Author(s):  
Paulo C. Coradi ◽  
Carlos H. P. Fernandes ◽  
Jean C. Helmich
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Initial Moisture Content ◽  
Effective Diffusivity ◽  
Isosteric Heat ◽  
Initial Water Content ◽  
Initial Water ◽  
Drying Time ◽  
Moisture Contents

ABSTRACT The aim of this study was to evaluate the influence of the initial moisture content of soybeans and the drying air temperatures on drying kinetics and grain quality, and find the best mathematical model that fit the experimental data of drying, effective diffusivity and isosteric heat of desorption. The experimental design was completely randomized (CRD), with a factorial scheme (4 x 2), four drying temperatures (75, 90, 105 and 120 ºC) and two initial moisture contents (25 and 19% d.b.), with three replicates. The initial moisture content of the product interferes with the drying time. The model of Wang and Singh proved to be more suitable to describe the drying of soybeans to temperature ranges of the drying air of 75, 90, 105 and 120 °C and initial moisture contents of 19 and 25% (d.b.). The effective diffusivity obtained from the drying of soybeans was higher (2.5 x 10-11 m2 s-1) for a temperature of 120 °C and water content of 25% (d.b.). Drying of soybeans at higher temperatures (above 105 °C) and higher initial water content (25% d.b.) also increases the amount of energy (3894.57 kJ kg-1), i.e., the isosteric heat of desorption necessary to perform the process. Drying air temperature and different initial moisture contents affected the quality of soybean along the drying time (electrical conductivity of 540.35 µS cm-1g-1); however, not affect the final yield of the oil extracted from soybean grains (15.69%).

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.

scholarly journals Temperature and seed moisture content affect electrical conductivity test in pea seeds

2017 ◽  
Vol 39 (4) ◽  
pp. 410-416 ◽  
Author(s):  
Lara Bernardes da Silva Ferreira ◽  
Nayara Alves Fernandes ◽  
Luan Costa de Aquino ◽  
Anderson Rodrigo da Silva ◽  
Warley Marcos Nascimento ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Moisture Content ◽  
Water Content ◽  
Initial Water Content ◽  
Seed Moisture Content ◽  
Initial Water ◽  
Test Efficiency ◽  
Seed Moisture ◽  
Pea Seeds ◽  
Initial Seed

Abstract: Several factors affect the electrical conductivity test efficiency, with emphasis given to the initial water content and the temperature during imbibition. This study aimed to evaluate the effect of the initial water content of pea seeds and the temperature on the electrical conductivity test efficiency. Six lots of ‘Mikado’ pea were used, which were previously tested for initial characterization. In the first trial, based on the initial value of the samples, the seed moisture content was adjusted to 9, 11, 13 and 15% and then the seeds were submitted to the electrical conductivity test. In the second trial, the water for seed imbibition was kept for 24 hours at 10, 15, 20, 25 and 30 ºC, and after that time the seeds were added and soaked for other 24 hours at the temperatures already mentioned. It was observed that initial seed moisture content and water temperature during imbibition influenced the results of the electrical conductivity test. This test should be carried out with distilled water, previously maintained for 24 hours at 25 °C for temperature stabilization. Then, the seeds with seed moisture content between 11 and 15% should be put to soak at 25 °C, and maintained at this temperature for 24 hours.

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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