scholarly journals Time rate of swelling of compacted highly plastic clay soil from Sudan

2018 ◽  
Vol 149 ◽  
pp. 02032 ◽  
Author(s):  
A M Elsharief ◽  
Mai Sufian
Keyword(s):  
Moisture Content ◽  
Clay Soil ◽  
Initial Moisture Content ◽  
Hyperbolic Model ◽  
Dry Density ◽  
Expansive Clay ◽  
Time Intervals ◽  
One Dimensional ◽  
Swell Percent ◽  
Three Stages

This paper investigates the development of swelling with time for a highly plastic and potentially expansive clay from Sudan. Soil samples were prepared in the laboratory at different moisture content values. The prepared samples were placed in the oedometer ring at three density levels and then placed in an oedometer cell which allows one dimensional swelling. Swelling was observed at different time intervals to 48 hours. The data was analyzed to determine the development of swelling with time. The data analysis clearly demonstrated three stages of swelling, initial, preliminary and secondary for all tested samples except the quasi-saturated ones. The swell percent and primary swelling were very sensitive to the initial moisture content and dry density of the tested samples. Most of the swelling took place during the first 24 hours for all the tested specimens. The hyperbolic model was assessed for prediction of the percent swell. The 12 hours data was found to be very successful in predicting the percentage swell.

scholarly journals Effect of Lime and Fly ash on Load Bearing Capacity of Expansive Clay soil

2019 ◽  
Vol 8 (11) ◽  
pp. 554-563
Keyword(s):  
Fly Ash ◽  
Moisture Content ◽  
Bearing Capacity ◽  
Clay Soil ◽  
Expansive Soil ◽  
Atterberg Limits ◽  
Dry Density ◽  
Index Test ◽  
Expansive Clay ◽  
Compaction Test

Expansive soil is a problematic soil which found in wide part of the world that has a high degree of sensitivity, nature of expansion and shrink behavior during water adding and removing this caused insufficient bearing capacity, excessive differential settlement and instability on excavation and embankment forming those conditions accelerate damage of building structure, road highway and dam. Attempt to undertake construction in such type of soil result will be bearing capacity failure, settlement problem. One of the well-known application of Lime and fly ash were improve Atterberg limits, compaction characteristics, bearing capacity and prevention of swelling problem of expansive clay that is why the main reason to select lime and fly ash in this project, both are good binding material to increase the cohesion force and shear strength of soil and assured to established rigid pavements and foundations. The mixing proportion of lime, fly ash and combination of lime and fly ash are (0%, 2 %, 4 % ), (10%, 15% ,20% ), (2 %+10 %, 2 % +15 %, 2 % +20 %) and (4 %+10 %, 4 % + 15 % , 4 %+ 20 %) with expansive soil respectively and then explored how much it modify the characteristics of soil like maximum dry density moisture content, consistency limits, FSI, UCS and CBR value which compare to untreated soil. Lime and fly ash treated soil carried out various tests Such as Moisture content test, consistency limit, compaction test, Unconfined Compression swelling index test and California bearing ratio test then after justify weather the bearing capacity of soil is good or not . Classification of soil was determined by conducting plasticity index and swelling index tests. Effect of lime and fly ash on soil index properties were assessed by conducting Atterberg limits test, strength of soil were assessed by conducting compaction test, UCS tests and CBR test and swelling properties were checked by conducting swelling index test. Expansive clay soil were mixed with lime, fly ash and combination of lime - fly ash by replacement process of soil and then cured for 7, 14 and 28 days.

scholarly journals Pengaruh Penambahan Abu Arang Tempurung Kelapa Pada Tanah Lempung Terhadap Hasil Uji Kompaksi

2021 ◽  
Vol 3 (2) ◽  
pp. 276-285
Author(s):  
Brigita Suzanna ◽  
Irwan Lie Keng Wong ◽  
Monika Datu Mirring Palinggi
Keyword(s):  
Specific Gravity ◽  
Moisture Content ◽  
Physical Properties ◽  
Clay Soil ◽  
Test Method ◽  
Coconut Shell ◽  
Dry Density ◽  
Coconut Shell Ash ◽  
American Society ◽  
Index Value

The purpose of this research is to determine the physical properties of clay soil and to analyze the effect of adding coconut shell charcoal ash to the clay soil. The soil samples used in this study came from Tanralili District, Maros Regency, two sample points were taken and the variations in the levels of addition of coconut shell charcoal ash is 0%, 4%, 6%, 8%, 10%. The test method used refers to ASTM (American Society for Testing Materials). The tests carried out were testing the physical properties of the soil in the form of moisture content, specific gravity, Atterberg boundaries, filter analysis, and hydrometer analysis, then a compaction test was carried out to determine the maximum soil density. The results of the test obtained a moisture content value of 28.811%, a specific gravity of 2.58 g / cm3 so that it is classified as organic clay. As well as the plasticity index value of 9.926% with moderate plasticity from the 7% -17% interval. Then from the test results of soil compaction testing with the addition of coconut shell ash, the dry density (gdry) equal to 0.862, 0.886, 0.914, 0.943, 0.962, this means that the soil sample experienced an increase in dry density (gdry) of 11.60%. From the research results it can be concluded that the addition of coconut shell charcoal ash can increase the value of soil dry density so that it can be used to increase the value of the carrying capacity of clay soil.

Research on Natural Settlement Rule of Dredged Silt in Tianjin Binhai Region

2013 ◽  
Vol 353-356 ◽  
pp. 548-553
Author(s):  
Xiao Qiang Liu ◽  
Yu Ting Zhang ◽  
Yan Hua Yang ◽  
Ming Ming Li
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Settlement Rate ◽  
Dead Weight ◽  
Main Research ◽  
Second Stage ◽  
Third Stage ◽  
Consolidation Settlement ◽  
Three Stages ◽  
Final Settlement

Main research object of this article is marine dredging silt in Tianjin Binhai region. It discusses natural settlement rule of dredged silt with different moisture content in Tianjin Binhai region through conducting indoor natural settlement model experiment to dredged silt of different moisture content. The results indicated that natural settlement of dredged silt in Tianjin Binhai region can be divided into three stages: the first stage is quick subsidence stage within 4-5 hours at the start of the experiment, during which settlement rate of dredged silt is fast and settlement volume is large; the second stage is natural deposition transition section stage within 2 days after the experiment, when settlement rate of dredged silt starts slow down but settlement volume is obvious; the third stage is dead-weight consolidation settlement stage of slow settlement after 2 days since the start of the experiment, in which settlement rate of dredged silt is slow and settlement volume is less. Settlement of Dredged silt in Tianjin Binhai region is greatly influenced by its initial moisture content. The higher the initial moisture content is the faster initial settlement rate of dredged silt will be and so is the final settlement volume of dredged silt.

Some factors affecting compacted clay swelling

1970 ◽  
Vol 7 (1) ◽  
pp. 79-91 ◽  
Author(s):  
A. Yevnin ◽  
D. Zaslavsky
Keyword(s):  
Moisture Content ◽  
Volume Change ◽  
Empirical Equation ◽  
Clay Soil ◽  
Initial Density ◽  
Initial Moisture Content ◽  
Swelling Pressure ◽  
Compacted Clay ◽  
Factors Affecting ◽  
Applied Loading

Volume change after saturation was determined on specimens of a statically compacted clay soil. It was found that density after swelling increases linearly with increasing initial density, initial moisture content, and increasing logarithm of applied loading pressure. An empirical equation with five coefficients and a constant, found with the aid of a computer, represents the results with a coefficient of correlation close to 1. An equation for the swelling pressure was also obtained from this equation. Results of specimens which consolidated did not fit the lines obtained for swelling. The relationships obtained were explained by the influence of particle reorientation and moisture content on swelling tendency.

Effects of Moisture on Temperature During Drying of Consolidated Porous Materials

1993 ◽  
Vol 115 (3) ◽  
pp. 724-733 ◽  
Author(s):  
F. Kallel ◽  
N. Galanis ◽  
B. Perrin ◽  
R. Javelas
Keyword(s):  
Moisture Content ◽  
Porous Materials ◽  
Moisture Transfer ◽  
Initial Moisture Content ◽  
Transfer Coefficients ◽  
One Dimensional ◽  
Excess Water ◽  
Brick And Mortar ◽  
Heat And Moisture ◽  
Simultaneous Heat

A one-dimensional model for simultaneous heat and moisture transfer in consolidated porous materials is solved for homogeneous brick and mortar slabs. It is validated by comparing numerically predicted moisture content and temperature evolutions with corresponding measured values. It correctly predicts that initially saturated slabs at 20°C which are suddenly placed in contact with air at 20°C and a relative humidity of 50 percent undergo a rapid transient reduction of their temperature down to 13°C due to the evaporation of excess water content. The model is used to study the effets of the initial moisture content and convection transfer coefficients on the minimum temperature of the slabs and on the duration of the transient.

Numerical Simulation of Unsaturated Evaporation and Drying Front Advancing in One-Dimensional Soil Columns

2013 ◽  
Vol 353-356 ◽  
pp. 730-734
Author(s):  
Zhang Hua ◽  
Gao Kang ◽  
Xiong Yi
Keyword(s):  
Great Influence ◽  
Coupled Model ◽  
Dry Density ◽  
Soil Columns ◽  
Total Evaporation ◽  
One Dimensional ◽  
Actual Evaporation ◽  
Constant Rate ◽  
Three Stages ◽  
Simulation Results

A coupled model of heat-moisture flow with Penman-Wilson evaporation boundary condition is used for simulating evaporation processes in three 1D vertical columns with different dry densities. The simulation results show that unsaturated evaporation process has three stages, i.e. constant-rate stage, falling-rate stage and residual stage. The depth of drying front has a great influence on soil actual evaporation. The actual evaporation decreases as the drying front advancing downward. The total evaporation decreased with the increase of soil dry density. The velocity of drying front advancing in the soil of higher dry density is faster than that of lower dry density.

scholarly journals Study on collapsibility of typical structural loess by multi-parameter comparative analysis

2021 ◽  
Vol 293 ◽  
pp. 01032
Author(s):  
Liu Hongcheng ◽  
Lu Changwei ◽  
Wang Yinxia ◽  
Song Yi ◽  
Guan Xiangfeng ◽  
...  
Keyword(s):  
Particle Size ◽  
Comparative Analysis ◽  
Moisture Content ◽  
Composite Structure ◽  
Structural Parameters ◽  
Initial Moisture Content ◽  
Clay Content ◽  
Dry Density ◽  
Particle Content ◽  
Multiple Groups

To study the collapsibility of typical loess and its influencing factors in different areas, the samples in Jingyang, Lanzhou and Yili were studied. The correlation between initial moisture content, dry density, composition of particle size, structural parameters and the coefficient of subsidence is analyzed. The results show that: the coefficient of collapsibility is negatively correlated with the initial moisture content and dry density. In the experiments of multiple groups, the collapsibility coefficient has a certain correlation with the clay content, but not a uniform correlation with the particle content. The collapse coefficient is approximately positively correlated with the composite structure potential.

scholarly journals Experimental Study on the Effect of Freezing and Thawing on the Shear Strength of the Frozen Soil in Qinghai-Tibet Railway Embankment

2022 ◽  
Vol 2022 ◽  
pp. 1-12
Author(s):  
B. Wang ◽  
J. H. Gao ◽  
Y. Q. Wang ◽  
X. J. Quan ◽  
Y. W. Gong ◽  
...  
Keyword(s):  
Growth Rate ◽  
Internal Friction ◽  
Moisture Content ◽  
Initial Moisture Content ◽  
Friction Angle ◽  
Frozen Soil ◽  
Internal Friction Angle ◽  
Freezing Process ◽  
Dry Density ◽  
Freezing And Thawing

The direct shear tests of different dry density and moisture content samples at different temperatures of the frozen soil in the Qinghai-Tibet Railway embankment between Tanggula South and Anduo section were carried out to analyze the influence rules of each experimental factor on the mechanical properties of frozen soil during the freeze-thaw process. The results show the following. (1) When the frozen soil temperature is below 0°C and continues to drop during the freezing and thawing process, each sample shows the law of a significant increase in cohesion and a slight decrease in the internal friction angle. In the meantime, the cohesion obtained during the thawing process of the sample at the same temperature point is higher than that obtained during the freezing process. In contrast, the internal friction angles exhibit an opposite law, where the internal friction angle during the melting process is lower than the internal friction angle during the freezing process. After freezing-thawing action, it deserves to be mentioned that the cohesion increases slightly while the internal friction angles present a slight decrease trend compared to the initial state. (2) With the decrease in temperature and the gradual increase in cohesion, the temperature curve can be divided into a fast-growing section from 0 to −2°C, a slow-growing section from −2 to −8°C, and a second fast-growing section from −8 to −10°C owing to the combined effect of the pressure-thawing action and ice-water phase change. In addition, the rate of decrease in the internal friction angle also shows a similar pattern. (3) The cohesion and the internal friction angle of samples both tend to increase first and then decrease with the rise of the initial moisture content, and the critical initial moisture content is near the optimal moisture content of 15%. (4) Both the cohesion and the internal friction angle of the samples increase with dry density growth. The growth rate of cohesion will gradually increase as the temperature decreases. Moreover, the growth rate of cohesion of low dry density samples is more susceptible to temperature, while the internal friction angle growth rate is not affected by temperature.

scholarly journals Influence of Freeze-Thaw Cycles on Mechanical Response of Levee Pavement

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Shuan Guo ◽  
Zheng Lu ◽  
Guokun Liu ◽  
Baoli Zhuang ◽  
Yongfeng Fan ◽  
...  
Keyword(s):  
Moisture Content ◽  
Mechanical Response ◽  
Triaxial Compression ◽  
Initial Moisture Content ◽  
Dry Density ◽  
Test Results ◽  
Freeze Thaw ◽  
Temperature Range ◽  
Pavement Structure ◽  
The Stability

The freeze-thaw cycles cause deterioration in mechanical properties of levee soil and further endanger the pavement structure on the embankment. This study attempts to comprehensively understand the mechanical response of pavement after freeze-thaw cycles. In this paper, the freeze-thaw cycles test under an open system was carried out, and then the triaxial compression test was conducted. Based on the test results, the effects of freeze-thaw cycles, temperature range, initial dry density, and initial moisture content of embankment soil on the mechanical response of road structure after freeze-thaw were calculated and analyzed. Finally, the stability of the slope of the levee was evaluated. The results show that the number of freeze-thaw cycles has the most significant impact on the mechanical response of pavement, the stress and strain of the structural layers vary in different ranges, and the pavement deflection increases by 5 times after 7 freeze-thaw cycles. However, the initial dry density and initial moisture content of the soil have little influence on the pavement structure, and the temperature range will exert an influence when it exceeds a certain threshold.

scholarly journals Experimental Study on Frost-Heaving Force Development of Tibetan Clay Subjected to One-Directional Freezing in an Open System

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Pengfei He ◽  
Meng Xiong ◽  
Yanhu Mu ◽  
Jianhua Dong ◽  
Xinlei Na
Keyword(s):  
Moisture Content ◽  
Open System ◽  
Freezing Temperature ◽  
Soil Samples ◽  
Dry Density ◽  
Time Lags ◽  
Frost Heaving ◽  
Moisture Contents ◽  
Three Stages ◽  
Directional Freezing

Frost heave of soils involves complex coupled interactions among moisture, heat, and stress, which can cause serious damage to cold regions engineering. In this paper, a series of one-directional freezing experiments were implemented for the Tibetan clay with rigid restraint in an open system. The varying characteristics of the temperature, frost-heaving force, and water replenishment during the freezing process were analyzed under different freezing temperatures (−5, −7, and − 9°C), dry densities (1.65, 1.7, and 1.75 g cm−3), and initial moisture contents (11, 14, and 17%) of the soil samples. It was concluded that the freezing of soil samples mainly occurred within 10–25 hours from the beginning of the experiment; hereafter, the soil temperatures tended to be stable. The development of frost-heaving force could be divided into three stages as slow increase, quick increase, and relative stable stages. Low freezing temperature, large dry density, and high moisture content were all the contributors to the frost-heaving process of the soil, which could increase the freezing depth, magnitude of the frost-heaving force, and amount of water replenishment. The variations in water replenishment from the open system corresponded to the three stages of the frost-heaving force but had time lags. The moisture contents at different layers of soil samples were measured after the freezing experiment. The results showed that the freeze part of soil samples experienced a significant wetting, while the unfrozen part experienced drying during the experiment. The degrees of wetting and drying were related to the freezing temperature, dry density, and initial moisture content of the soil samples. The experiment results could provide data support for theoretical study on moisture, heat, and stress coupling in freezing soil.

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