Effect of Adding Sand on Clayey Soil Compressibility

2020 ◽  
Vol 857 ◽  
pp. 328-333
Author(s):  
Yasir M. Al-Badran
Keyword(s):  
Clayey Soil ◽  
Clay Content ◽  
Unit Weight ◽  
Compression Index ◽  
Dry Unit Weight ◽  
Soil Compressibility ◽  
Soil Components ◽  
Good Agreement

The effect of adding sand on clayey soil compressibility is investigated in this study. Four different percentage of clay-sand mixtures are used; 100% clay with 0% sand named 100C, 30% clay with 70% sand named 30C-70S, 15% clay with 85% sand named 15C-85S, and 100% sand named 100S. The used clay was obtained from Baghdad city in Iraq and classified as CH soil, while the used sand was taken from the sand quarry in Al-Khider area from Al-Muthana Governorate in Iraq and classified as SW soil. The initial dry unit weight for all mixtures is 18 kN/m3. The results show that the variations of the soil compressibility properties with soil components content changes almost linearly The results show that the preconsolidation stress (Pc) decreases with 19% and 38% and the rebound index (Cr) decreases with 4 and 53% and the compression index (Cc) decreases with 39 and 68% as the sand percentage increases with 70 and 85% respectively. Finally, predicted (fitting) Equations are achieved for the change of the soil compressibility properties with clay content with good agreement.

scholarly journals Evaluations of the effects of soil properties and electrical conductivity on the water content reflectometer calibration for landfill cover soils

2017 ◽  
Vol 12 (No. 1) ◽  
pp. 10-17 ◽  
Author(s):  
K. Kim ◽  
J. Sim ◽  
T.-H. Kim
Keyword(s):  
Electrical Conductivity ◽  
Soil Properties ◽  
Water Content ◽  
Clay Content ◽  
Liquid Limit ◽  
Time Domain Reflectometry ◽  
Volumetric Water Content ◽  
Unit Weight ◽  
Landfill Cover ◽  
Dry Unit Weight

This study presents soil-moisture calibrations using low-frequency (15–40 MHz) time domain reflectometry (TDR) probe, referred to as water content reflectometer (WCR), for measuring the volumetric water content of landfill cover soils, developing calibrations for 28 different soils, and evaluating how WCR calibrations are affected by soil properties and electrical conductivity. A 150-mm-diameter PVC cell was used for the initial WCR calibration. Linear and polynomial calibrations were developed for each soil. Although the correlation coefficients (R<sup>2</sup>) for the polynomial calibration are slightly higher, the linear calibrations are accurate and pragmatic to use. The effects of soil electrical conductivity and index properties were investigated using the slopes of linear WCR calibrations. Soils with higher electrical conductivity had lower calibration slopes due to greater attenuation of the signal during transmission in the soil. Soils with higher electrical conductivity tended to have higher clay content, organic matter, liquid limit, and plasticity index. The effects of temperature and dry unit weight on WCR calibrations were assessed in clayey and silty soils. The sensor period was found to increase with the temperature and density increase, with greater sensitivity in fine-textured plastic soils. For typical variations in temperature, errors in volumetric water content on the order of 0.04 can be expected for wet soils and 0.01 for drier soils if temperature corrections are not applied. Errors on the order of 0.03 (clays) and 0.01 (silts) can be expected for typical variations in dry unit weight (± 2 kN/m<sup>3</sup>).

scholarly journals Thermal Conductivity of Some Ice-rich Permafrost Soils

1975 ◽  
Vol 12 (3) ◽  
pp. 413-424 ◽  
Author(s):  
W. A. Slusarchuk ◽  
G. H. Watson
Keyword(s):  
Thermal Conductivity ◽  
Heat Source ◽  
Water Content ◽  
Northwest Territories ◽  
Unit Weight ◽  
Dry Unit Weight ◽  
Laboratory Conditions ◽  
Permafrost Soils ◽  
Field And Laboratory Conditions ◽  
Good Agreement

Values are presented for the thermal conductivity of frozen and thawed ice rich permafrost soils from Inuvik, Northwest Territories, measured under field and laboratory conditions with a cylindrical heat source. Samples were shipped to Ottawa, Canada, in the frozen condition at temperatures ranging from –5 to –70 °C. It was found that temperature of shipping and repositioning of the probe between measurements had no statistically significant effect on results. The dependence of thermal conductivity on bulk unit weight and dry unit weight is given for both frozen and thawed samples. Measured thermal conductivities were found to be in good agreement with other values obtained for similar soils and corresponding unit weight and water content.

scholarly journals MOLECULAR WEIGHT AND ELECTROPHORESIS OF CRYSTALLINE RIBONUCLEASE

1940 ◽  
Vol 24 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Alexandre Rothen
Keyword(s):  
Molecular Weight ◽  
Isoelectric Point ◽  
Unit Weight ◽  
Diffusion Measurement ◽  
Average Value ◽  
Rate Of Sedimentation ◽  
And Diffusion ◽  
Good Agreement

Electrophoretic studies on purified crystalline ribonuclease showed the absence of any impurities differing in mobility from the bulk of material. The isoelectric point of ribonuclease was found by electrophoresis to be at about pH 7.8. Ultracentrifuge studies indicated fair homogeneity of ribonuclease in solution. Only one moving component has been observed. The molecular weight of ribonuclease was found to be 12,700 from rate of sedimentation (S25 = 1.85 x 10–13 in 0.5 M (NH4)2SO4) and diffusion measurement (D = 1.36 x 10–6 in 0.5 M (NH4)2SO4), in good agreement with the average value of 13,000 found from equilibrium measurements. This low value for the molecular weight of a protein would seem to discredit the value 17,600 as representing a universal unit weight for proteins in general.

Dry unit weight of compacted soils prediction using GMDH-type neural network

2017 ◽  
Vol 132 (8) ◽  
Author(s):  
Mahmoud Hassanlourad ◽  
Alireza Ardakani ◽  
Afshin Kordnaeij ◽  
Hossein Mola-Abasi
Keyword(s):  
Neural Network ◽  
Unit Weight ◽  
Compacted Soils ◽  
Dry Unit Weight

Study on Incipient Motion of Consolidated Cohesive Fine Sediment

2012 ◽  
Vol 204-208 ◽  
pp. 354-358
Author(s):  
Jun Wang ◽  
Wei Guo ◽  
Hai Tao Xu ◽  
Zhong Wu Jin ◽  
Yin Jun Zhou
Keyword(s):  
Particle Size ◽  
Shear Stress ◽  
Critical Shear Stress ◽  
Fine Sediment ◽  
Weight Increase ◽  
Unit Weight ◽  
Incipient Motion ◽  
Mean Particle Size ◽  
Dry Unit Weight ◽  
The One

The incipient motion mechanism of cohesive fine sediment is different to the one of non-cohesive sediment. It is related to the consolidation while being influenced by the dry unit weight and particle size. By means of the rectangle piping flume, the influence mechanism of dry unit weight and particle size to critical shear stress of cohesive fine sediment is studied. Experimental results show that on the condition of consolidation, the influence of dry unit weight to incipient motion is divided into two different stages, one is that when dry unit weight increase quickly, but the influence to incipient motion is not greatly, another is that when dry unit weight increase slowly, but the influence to incipient motion is very greatly, the critical dry unit weight to two stages decline as mean particle size decrease. So the mean particle size is finer, the degree of dry unit weight influence to critical shear stress is stronger, and the incipient motion is more difficult when consolidation last longer; it is also shown consolidation is more disadvantageous to incipient motion.

Geotechnical Parameters of Composite Soil

2011 ◽  
Vol 308-310 ◽  
pp. 1651-1655 ◽  
Author(s):  
Amin Chegenizadeh ◽  
Hamid Nikraz
Keyword(s):  
Natural Fiber ◽  
Fiber Content ◽  
Unit Weight ◽  
Embankment Dam ◽  
Geotechnical Parameters ◽  
Dry Unit Weight ◽  
Optimum Water Content ◽  
Compaction Characteristic ◽  
Optimum Water ◽  
Compaction Behaviour

Composite soils have been widely used in civil engineering applications, especially in slopes, embankment dam and landfills. This paper aims to investigate effect of fiber inclusion on compaction characteristic of composite soil (i.e. clay composite). A series of laboratory tests carried out to evaluate fiber effect on optimum water content and maximum dry unit weight of composite soils. Clay was selected as soil part of the composite and natural fiber was used as reinforcement. The fiber parameters differed from one test to another, as fiber length varied from 10 mm to 25mm and fiber content were selected as 0.1% and 0.3%. For each test, compaction curved derived and the results were compared. The results proved that inclusion of fiber affected compaction behaviour of samples so that increasing in fiber content and length caused increasing in Optimum Moisture Content (OMC) and slightly decreased maximum dry unit weight.

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