Engineering Aspects of Soils

1999 ◽  
Author(s):  
Robert F. Keefer
Keyword(s):  
Soil Properties ◽  
Water Content ◽  
Soil Mechanics ◽  
Liquid Limit ◽  
Atterberg Limits ◽  
Engineering Properties ◽  
Coarse Grained ◽  
Fine Grained ◽  
Coarse Material ◽  
Semi Solid

Although most landscape architects use soils primarily for growing plants, sometimes they need to know how engineers look at soils. Engineers are not concerned about soil properties that relate to growing plants. Engineers consider soil as a support for building foundations, use in earthworks, a place for burying pipes that carry electricity, water, gas or oil, and as a tool for disposing of hazardous, municipal, industrial, and household wastes. Soil properties that engineers consider important are hydraulic conductivity (permeability), compressive strength, shear strength, and lateral pressures. Soil mechanics deals with stress/strain/time relationships. Some engineering properties of a soil that describe the relation of clays to water content were studied by a Swedish scientist, Atterberg, in 1911. Soil clays based on water content were categorized into solid, semi-solid, plastic, and liquid. The dividing lines between each of these four states are known as the “Atterberg limits,” that is, shrinkage limit (from solid to semisolid), plastic limit (from semi-solid to plastic), and liquid limit (from plastic to liquid). These points can be measured for individual clays. The Atterberg limits are used by engineers to classify soils based on their moisture properties. These limits are particularly useful for evaluating soil compressibility, permeability, and strength. The plasticity of a clay soil depends on the type and amount of clay mineral and organic materials present. Plasticity is the reaction a soil has to being deformed without cracking or crumbling. The “liquid limit” is a term indicating the amount of water in a soil between the liquid state and the plastic state. Soils are first divided into two categories of coarse-grained and fine-grained. Coarse-grained soils are those in which more than half of the material is larger than a no. 200 sieve. Fine-grained soils are those in which more than half of the material is smaller than a no. 200 sieve. Coarse-grained soils are further divided into two categories of gravels and sands. Gravels are those with more than half of the coarse material larger than a no. 4 sieve. Sands are those with more than half of the coarse material smaller than a no. 4 sieve.

scholarly journals A Preliminary Study on the Engineering Properties of Clay Soil

2019 ◽  
Vol 2 (2) ◽  
pp. 39-40
Author(s):  
Mehrin Hoque ◽  
Akhila Palat ◽  
Michael Hendry
Keyword(s):  
Clay Soil ◽  
Saline Water ◽  
Soil Mechanics ◽  
Field Work ◽  
Atterberg Limits ◽  
Engineering Properties ◽  
Clay Soils ◽  
Climate Conditions ◽  
Semi Solid ◽  
Compare And Contrast

Karl Von Terzaghi, the father of soil mechanics, says, “There is no other soil which is as problematic as clay soil”. In many places across the badlands of Alberta, clay soil is known to be troublesome and cause issues with buildings and infrastructure. Climate conditions, erosion and weathering can cause the unstable clay soil to create landslides, which consequently damage many of these structures. For this reason, engineers are sent to these sites to monitor and collect data over a period of time to compare and contrast their results. The purpose of this study is to learn and understand the properties of clay soils through different classification and index tests. Two clay soils, kaolinite and bentonite, were tested for their properties and their results were compared. Some of the tests performed include the hydrometer analysis, pycnometer analysis, and atterberg limits. The hydrometer analysis is the process in determining the size of silts and clays (when sieves cannot be used). The pycnometer analysis is used to determine the specific gravity of a substance. Atterberg limits are used to determine the water content at which a soil starts to shift from liquid, plastic or semi-solid. These tests were done in two different solutions - one containing distilled water and one with saline water - to understand the effect of the solution on the liquid and plastic limits. The goal of this study was achieved and the results can be used to understand more about the engineering properties of clay soils and apply these studies to future field work. By understanding these properties, further research can be done to discover long term solutions to landslides caused by the problematic soil.

scholarly journals Compressibility behaviour of remoulded, fine-grained soils and correlation with index properties

2000 ◽  
Vol 37 (3) ◽  
pp. 712-722 ◽  
Author(s):  
A Sridharan ◽  
H B Nagaraj
Keyword(s):  
Liquid Limit ◽  
Plasticity Index ◽  
Engineering Properties ◽  
Test Results ◽  
Index Properties ◽  
Initial Water ◽  
Fine Grained ◽  
Wide Range ◽  
The Relationship ◽  
Water Contents

Correlating engineering properties with index properties has assumed greater significance in the recent past in the field of geotechnical engineering. Although attempts have been made in the past to correlate compressibility with various index properties individually, all the properties affecting compressibility behaviour have not been considered together in any single study to examine which index property of the soil correlates best with compressibility behaviour, especially within a set of test results. In the present study, 10 soils covering a sufficiently wide range of liquid limit, plastic limit, and shrinkage limit were selected and conventional consolidation tests were carried out starting with their initial water contents almost equal to their respective liquid limits. The compressibility behaviour is vastly different for pairs of soils having nearly the same liquid limit, but different plasticity characteristics. The relationship between void ratio and consolidation pressure is more closely related to the shrinkage index (shrinkage index = liquid limit - shrinkage limit) than to the plasticity index. Wide variations are seen with the liquid limit. For the soils investigated, the compression index relates better with the shrinkage index than with the plasticity index or liquid limit.Key words: Atterberg limits, classification, clays, compressibility, laboratory tests.

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>).

The correlation of index properties with some basic engineering properties of soils

1978 ◽  
Vol 15 (2) ◽  
pp. 137-145 ◽  
Author(s):  
C. P. Wroth ◽  
D. M. Wood
Keyword(s):  
Soil Mechanics ◽  
Liquid Limit ◽  
Engineering Properties ◽  
Cone Penetrometer ◽  
Plastic Limit ◽  
The North ◽  
The United Kingdom ◽  
Liquidity Index ◽  
Remoulded Soil ◽  
The North Sea

Experimental evidence is produced to show that it is reasonable to assign a unique strength to all soils when at their respective liquid limits, and to redefine the plastic limit as the water content at which the strength is 100 times that at the liquid limit. Combining these assumptions with ideas of critical state soil mechanics it is then possible to relate the compression index of the remoulded soil to its plasticity index, and to suggest a unique relation between remoulded strength and liquidity index, irrespective of actual values of liquid and plastic limits. Field data from the Gulf of Mexico and from the North Sea are presented in support of these relations. The predictions of strength are best for overconsolidated clays, having water contents near the plastic limit.Recently in the United Kingdom the cone penetrometer has become the recommended test for determination of the liquid limit, in preference to the Casagrande test. Having redefined the plastic limit it would be logical to use the cone penetrometer to determine this too, by using cones with different weights. Experimental data are shown to illustrate and support this proposal.

Comparing the efficiency of ordinary kriging and cokriging to estimate the Atterberg limits spatially using some soil physical properties

Clay Minerals ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 181-193 ◽  
Author(s):  
O. Baskan ◽  
G. Erpul ◽  
O. Dengiz
Keyword(s):  
Ordinary Kriging ◽  
Mean Squared Error ◽  
Field Capacity ◽  
Liquid Limit ◽  
Atterberg Limits ◽  
Engineering Properties ◽  
Soil Parameters ◽  
Regression Equations ◽  
Soil System ◽  
The Mean

AbstractThe spatial distribution of the Atterberg limits can be used to distinguish the consistency and behaviour of a soil and its engineering properties, which strongly depends on the water content of the soil and types of silts and clays in the soil. By spatial modeling, and comparing the results of ordinary kriging with the cokriging approach, this study aims to find correlations between the Atterberg limits and the selected physical soil parameters in order to examine how effective they are in generating an understanding of the dynamics of a physical soil system.In 156 soil samples, the Atterberg limits and soil moisture conditions were determined, and auxiliary functions were selected by application of cokriging using correlation analysis and regression equations obtained by the residual maximum likelihood (REML). These techniques were evaluated by the results of the mean absolute error (MAE) and the mean squared error (MSE). Cokriging analysis was found to be more effective at estimating the liquid limit (WLL) and the plastic limit (WPL) than kriging analysis and with smaller error values. On the other hand, the kriging approach, which had smaller MAE and MSE values, was more effective at estimating the plasticity index (WPI) values than the cokriging method. Unlike the REML regression equations, the field capacity (FC) value was the more suitable parameter for the cokriging estimates. When the necessary labour and time were considered for determining the Atterberg limits, both kriging and cokriging were found to be applicable for estimation of these limits.

scholarly journals Remediation of Clayey Soil Using Silica Fume

2018 ◽  
Vol 162 ◽  
pp. 01017
Author(s):  
Kawther Al-Soudany
Keyword(s):  
Silica Fume ◽  
Clayey Soil ◽  
Liquid Limit ◽  
Engineering Properties ◽  
Unit Weight ◽  
Clay Material ◽  
Fine Grained ◽  
Pozzolanic Reactivity ◽  
Fine Grained Soil ◽  
Swell Pressure

This paper evaluates the use of silica fumes as modification of fine-grained soil in order to alter undesirable properties of the native soil and create new useful soils. Silica fume as well as clay material, are used in changing the engineering properties to be compatible and satisfying this is due to their pozzolanic reactivity. The study aims to investigate the uses of these materials in geotechnical engineering and to improve the properties of soils. Four percentages of silica fumes were used in the present study, which is 0, 3, 5 and 7%. Classification, specific gravity, compaction characteristics, swell and swell pressure, CBR and compressive strength tests had been conducted on the prepared and modified soils. Results clarified that the silica fume increasing leads to decrease the plasticity index and liquid limit. Increasing in silica fume causes an increasing in plastic limit and optimum water contents while the maximum dry unit weight values decrease. The compressive shear strength, California Bearing Ratio (CBR), swell and swell pressure is improved by using silica fume so that silica fume can be considered as a successful material in improving the soil properties.

The Application of Vapour Equlibrium Technique in Water Retention Study of Fine Grained Tailings

2013 ◽  
Vol 838-841 ◽  
pp. 1785-1790
Author(s):  
Qing Hua Jiang ◽  
Chen Xiang Yu
Keyword(s):  
Water Retention ◽  
Characteristic Curve ◽  
Size Composition ◽  
Engineering Properties ◽  
Coarse Grained ◽  
Dry Density ◽  
Soil Suction ◽  
Fine Grained ◽  
Theoretical Support ◽  
Tailing Dam

As a problematic material, fine grained tailings have many particular engineering characteristics and seriously affect the safety and stability of the tailing dam body. These engineering properties are closely related to moisture migration and soil suction under different water content. This article chose fine grained tailings of Li Tie Lan Ting tailings dam in Zhejiang province as an example, and measured the soil water characteristic curve (SWCC) of fine grained tailings with different partical size composition and dry density using vapour equilibrium technique. Efforts have also been made to demonstrate the influences of soil type, dry density on water retention. The study result shows that particle-size composition has a significant impact on SWCCs of the tailings. Finer grained samples have lower water loss rate and higher water-holding capacity than coarse grained samples in the same suction state. Contrary with low suction stage, dry density has negligible influence on the soil suction, and parameters effect SWCCs at high suction stage. The research results may provide a theoretical support and a beneficial reference for further research of fine grained tailingss engineering properties.

scholarly journals Measurement of Degree of Compaction of Fine-Grained Soil Subgrade Using Light Dynamic Penetrometer

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Junhui Zhang ◽  
Yongsheng Yao ◽  
Jianlong Zheng ◽  
Xiangqun Huang ◽  
Tian Lan
Keyword(s):  
Water Content ◽  
Field Tests ◽  
Prediction Equation ◽  
Liquid Limit ◽  
Fine Grained ◽  
Penetration Ratio ◽  
Good Consistency ◽  
Fine Grained Soil ◽  
Measured Water ◽  
Water Contents

To determine the degree of compaction of subgrades filled with fine-grained soil, the compaction test and light dynamic penetrometer (LDP) test were carried out for low liquid-limit clay samples with different water contents in laboratory. Then, a prediction equation of the penetration ratio (PR) defined as the depth per drop of the hammer of LDP, degree of compaction (K), and water content (ω) was built. After that, the existing fine-grained soil subgrades on LDP-based field tests were excavated. The on-site PR values, water contents, and degrees of compaction of slopes were obtained. The estimated degrees of compaction using the prediction equation were compared with measured values of the degree of compaction in field. The results show that there is good consistency between them, and an error within 3.5% was obtained. In addition, the water content should be determined firstly while using the prediction equation which is proposed in this study. Therefore, a numerical method of the water content of a subgrade was developed, and the predicted and measured water contents were compared, which shows a relatively high relativity. Then, the degree of compaction of fine-grained soil subgrades can be calculated according to the predicting equation, which involves the penetration ratio (PR) and the numerically calculated water content as input instead of the measured value in the field.

Experimental Study on Temperature Effect on Engineering Properties of Clayey Soils

2012 ◽  
Vol 512-515 ◽  
pp. 1905-1918
Author(s):  
Yu Xian Shao ◽  
Bin Shi ◽  
Chun Liu ◽  
Lei Gao
Keyword(s):  
Shear Strength ◽  
Temperature Effect ◽  
Water Content ◽  
Free Water ◽  
Adsorbed Water ◽  
Liquid Limit ◽  
Engineering Properties ◽  
Dry Density ◽  
Clayey Soils ◽  
Increasing Temperature

Temperature significantly influences the engineering properties of clayey soil and this temperature effect usually depends on soil type. In this investigation, laboratorial experiments were conducted on three soils to evaluate the adsorbed water content, Atterberg limits, swelling, shear strength and permeability under different temperatures (5-50°C). The results indicate that liquid limit decreases, swelling increases, permeability increases with increasing temperature. It is fundamentally due to the change of adsorbed water content. Hydrophilic minerals, which contain large amounts of adsorbed water, play an important role in the temperature effect. With the increase of hydrophilic minerals, the temperature effect on liquid limit increases and the effect on swelling ratio decreases. The hydrophilic minerals content also has significant impact on the temperature effect of permeability. With increasing temperature, the adsorbed water is transformed to free water, and then the permeability may increase significantly. The shear strength of clayey soils with higher content of hydrophilic mineral is more sensitive to temperature variation. The cohesive force mainly changes linearly with the temperature. Different phenomena, i.e. thermal-hardening or thermal-softening, was observed on strength behaviour due to different hydrophilic mineral content, moisture content and dry density of sample.

scholarly journals EFFECTS OF MECHANICALLY STABILIZED GRADED ASSORTED COARSE-GRAINED SOILS IN THE PERFORMANCE OF UNPAVED ROAD: A CASE STUDY IN GOFFA ZONE, SAWLA AREA

2019 ◽  
Vol 7 (8) ◽  
pp. 133-156
Author(s):  
Edire Erko Esho ◽  
Emer Tucay Quezon ◽  
Democracy Dila
Keyword(s):  
Addis Ababa ◽  
Liquid Limit ◽  
Engineering Properties ◽  
Coarse Grained ◽  
Unpaved Road ◽  
Course Materials ◽  
Undisturbed Samples ◽  
Road Project ◽  
Base Course ◽  
Mechanically Stabilized

Road network development in Ethiopia is booming, radiating from Addis Ababa towards North-South directions, and East-West directions, due to the good economic growth of the country. However, there are challenges always facing by the pavement designers, and materials engineers for every road project, specifically the unpaved roads in Goffa Zone. It was because, most parts of the existing unpaved road sections within the study area are heavily damaged, and lack of proper maintenance. The source of good quality of sub-base course materials limited and becoming depleted. It is for this reason that the research study focused on the investigation of the effects of mechanically stabilized graded assorted coarse-grained soils. Disturbed and undisturbed samples from different quarry sites were considered and tested in the laboratory. Laboratory test for each location performed, and the results served as control values of the engineering properties of natural soils. The Disturbed samples tested for Gradation, Atterberg's Liquid Limit Tests, and Compaction, while, the undisturbed sample tested for the CBR strength, using ASTM manual. The results of the assorted materials for the sub-base course was analyzed and compared with the AASHTO and ERA Standard Specifications.

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