Preview

Soil

Powerful Essays
Open Document
Open Document
1715 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Soil
OUTLINE
• Introduction and Terminology

Advanced
Advanced Soil Mechanics &
Foundation Design
UNSATURATED SOIL
MECHANICS
A/Prof Hadi Khabbaz
Email: hadi.khabbaz@uts.edu.au

• Suction and Measurement Methods
• Effective Stress Concept for Unsaturated
Soils
• Soil Water Characteristic Curve (SWCC)
Ch
(SWCC)
• Permeability of Unsaturated Soils
• Shear strength of Unsaturated Soils
• Examples
• Conclusions

Room 2.511B

Introduction
&
Terminology

State whether the following statements are True or False
1. Soils below water tables are fully saturated.
Soils belo tables are sat 2. All soils above water table are unsaturated.
3. Compacted soils are generally unsaturated soils.
4. Shear strength of a saturated clayey sand is greater than its unsaturated shear strength.

Why do we need to understand
Unsaturated Soil
Mechanics?

Most of the natural soil systems are in arid and semiarid regions and soils subjected to seasonal moisture deficits are in an unsaturated state.
Who needs unsaturated soil mechanics?
Every geotechnical engineer needs to be aware of the th role played by the portion of soil with negative porepressure (i.e. generally the portion above the water table). Many present solutions in soil mechanics and foundation design are quite approximate and based on saturated soils. More research is still required.

1

Stress Distribution during the desiccation of a soil

Stress Distribution during the desiccation of a soil

Certainly there is a need for an appropriate technology for unsaturated

soil behaviour.

Such technology must:
1. Be practical
2. Not be too costly to employ
3. Have a sound theoretical basis
4. Run parallel in concept of conventional soil mechanics

2

Basic Differences between Saturated and
Unsaturated Soils

Nature
Existing of Air

Engineering Behaviour
Negative Pore Water
Pressure

Air

Water

Solid Particles

Compression?
1/P

Compression?
Cf
Continue Reading
View Writing Issues

You May Also Find These Documents Helpful

  • Satisfactory Essays

    Soil Survey Exercise Pender Codocx 2
    • 251 Words
    • 3 Pages

    Soil Survey Exercise Pender Codocx 2

    For the dominant soil type and potential land uses listed below, characterize the limitation for each…

    • 251 Words
    • 3 Pages
    Satisfactory Essays
    Read More
  • Good Essays

    Soil and Organic Matter
    • 743 Words
    • 3 Pages

    Soil and Organic Matter

    Position of Layers | One at top of tube and one in middle of tube | Two at top of tube and two in middle of tube | Two layers at top of tube, one layer in middle of tube and two layers at bottom of tube | Two layers at top of tube, and one layer filling up half of tube |…

    • 743 Words
    • 3 Pages
    Good Essays
    Read More
  • Good Essays

    Texture Triangle Worksheet
    • 823 Words
    • 4 Pages

    Texture Triangle Worksheet

    1. Soil Profiles – go to this site APES in A Box: Soil Profiles and take notes on the soil horizons: http://www.youtube.com/watch?v=6Kr3Wj7SeSc…

    • 823 Words
    • 4 Pages
    Good Essays
    Read More
  • Good Essays

    Soil and Glaciers
    • 630 Words
    • 3 Pages

    Soil and Glaciers

    Soils have been classified according to a system developed by soil scientists and the U.S. Soil Conservation Service. Using this classification system of soil orders, pick two locations on Earth, one in your current area and another area, and describe the order and the conditions that define it. (See Figure 4.12 in the textbook.)…

    • 630 Words
    • 3 Pages
    Good Essays
    Read More
  • Good Essays

    Geography And Vegetation Regions Assessment
    • 1273 Words
    • 6 Pages

    Geography And Vegetation Regions Assessment

    The natural vegetation regions and soil regions are interconnected in numerous ways. Soil regions as the Tundra soils, or dry climate soils have the potential to affect the type of vegetation that can be grown. Where you would find cold temperatures as the Tundra, you can expect limited vegetation to grasses, mosses, and shrubs. Because the ground has an active layer of permafrost, growing conditions are not suitable for plants and trees. Areas with moist soil as the wet-climate regions, you are expected to find trees and plants resembling the mixed forests, boreal and taiga forest, as well the deciduous forests. The Grasslands are located in the dry climate soils situated in the Prairie Provinces. Due to the dry temperatures there are very insufficient amount of trees, and consisting of large rolling terrains of grasses. To conclude location is a dependent factor on the type of vegetation a region will come to…

    • 1273 Words
    • 6 Pages
    Good Essays
    Read More
  • Good Essays

    Deforestation In Haiti
    • 649 Words
    • 3 Pages

    Deforestation In Haiti

    The first biophysical factor affecting soil is its topography, 75% of the land is mountainous with more than 60% of land with a gradient greater than 20%, even without human intervention, Haiti has a natural high risk of erosion. The second biophysical factor is its soil type. There are 4 major subtypes, Udepts and Usteps that are newly formed shallow soil that can support forests and grasslands. Fluvents that are shallow and sandy and so susceptible to leaching where the rate of soil erosion exceeds the rate of soil formation and Udults that are heavily leached acidic forests and has a very low fertility requiring additional nutrients to support successful crop production. Another factor is the bimodal rainfall pattern. Haiti has a tropical climate with two annual rainy seasons; April - June and August - November. These climatic conditions cause erosion by wind during periods of moisture deficit and by water during periods of moisture surplus. The differences in soil types means that there is a limited amount of cultivable land. Soil surveys by the US Department of Agriculture in 1980 state that only 11.3% of the land is suitable for crops, 31.7% is suitable for crops but with some restriction, 2.3% mediocre due to poor drainage system but acceptable for rice cultivation and 54.7% is suitable for tree crops or pastures due to severe erosion and steep…

    • 649 Words
    • 3 Pages
    Good Essays
    Read More
  • Satisfactory Essays

    Types of Soil Matrix
    • 403 Words
    • 2 Pages

    Types of Soil Matrix

    OxisolsUltisolsVertisolsAlfisolsSpodosolsMollisolsAridisolsHistosolsEntisolsInceptisolsAndisolsGroup11111112333CharacteristicsVery old, highly weathered soils of low latitudes. Subsurface horizon of accumulation of mineral oxides and very low base status. Soils of equatorial, tropical, and subtropical latitude zones, with a subsurface horizon of clay accumulation and low base status. Soils of subtropical and tropical zones with high clay content and high base status. Vertisols develop deep, wide cracks when dry, and the soil blocks formed by cracking move with respect to each other.Soils of humid and sub humid climates with a subsurface horizon of clay accumulation and high base status. Alfisols range from equatorial to subarctic latitude zones. Soils of cold, moist climates, with a well-developed B horizon of illuviation and low base status.Soils of semiarid and sub humid midlatitude grasslands, with a dark, humus-rich epipedon and very high base status.Soils of dry climates, low in organic matter, and often having subsurface horizons of accumulation of carbonate minerals or soluble salts.Soils with a thick upper layer very rich in organic matter.. Soils lacking horizons, usually because their parent material has accumulated only recently.Soils with weakly developed horizons, having minerals capable of further alteration by weathering processesSoils with weakly developed horizons, having a high proportion of glassy volcanic parent material produced by erupting volcanoes.Regions of…

    • 403 Words
    • 2 Pages
    Satisfactory Essays
    Read More
  • Good Essays

    Physical And Chemical Properties Of Soil Lab Report
    • 1104 Words
    • 5 Pages

    Physical And Chemical Properties Of Soil Lab Report

    Soil properties: Some physical and chemical properties of the soil were measured, which are presented in Table 1. The availability of nutrients and even contaminants depends on the degree of soil acidity. The most suitable pH for soil microorganism’ activity is 7, as nutrient solubility depends on soil pH changes (Riser-Roberts, 1998). The soil used in the present study has neutral pH and therefore does not limit the activity of microorganisms or the solubility of nutrients except for phosphorus.…

    • 1104 Words
    • 5 Pages
    Good Essays
    Read More
  • Powerful Essays

    Effect of Soil Compaction on Root Growth and Nutrient Uptake by Crop Plants with Special Reference to Wetland Rice Cultivation
    • 3813 Words
    • 16 Pages

    Effect of Soil Compaction on Root Growth and Nutrient Uptake by Crop Plants with Special Reference to Wetland Rice Cultivation

    The compaction of soil can be defined as an increase in its dry density,and closer packing of solid particles or reduction in porosity (McKyes,1985).In other words, soil compaction is a dynamic soil behavior by which the state of compaction is increased (Gill and Vanden Berg, 1967). Soehne (1958 ) determined that for arable soils compaction could be described by the following relationships: n = - A ln P + C Where, n = porosity, C = porosity obtained by compacting loose soil at a pressure of 10 psi, A = slope of the respective plotted…

    • 3813 Words
    • 16 Pages
    Powerful Essays
    Read More
  • Better Essays

    Lab Report - Liquid and Plastic Limit
    • 994 Words
    • 4 Pages

    Lab Report - Liquid and Plastic Limit

    To determine the Liquid Limit, Plastic Limit, Plasticity Index and the soil classification according to UCS classification.…

    • 994 Words
    • 4 Pages
    Better Essays
    Read More
  • Good Essays

    Constant-Head Permeability Test.
    • 921 Words
    • 4 Pages

    Constant-Head Permeability Test.

    In the design of engineering projects, one of the most important soil properties of interest to the soils engineer is permeability. To some degree, permeability will play a role in the design of almost any structure. For example, the durability of concrete is related to its permeability. In designs that make use of earthen materials (soils and rock, etc.) the permeability of these materials will usually be of great importance.…

    • 921 Words
    • 4 Pages
    Good Essays
    Read More
  • Satisfactory Essays

    Core Syllabus
    • 353 Words
    • 3 Pages

    Core Syllabus

    The final module revisits the major themes of the course, from the perspective of how they might be affected by changes already underway, or predicted in the foreseeable future. Both threats and prospects are examined, from the possibility of a global pandemic to the implications of genetic engineering and nanotechnology. The course concludes with reflection on what we’ve learned over the semester and addresses our ongoing hopes and fears for the future, speculating on what we can do with this knowledge.…

    • 353 Words
    • 3 Pages
    Satisfactory Essays
    Read More
  • Better Essays

    Soil Management in Konkan
    • 3415 Words
    • 14 Pages

    Soil Management in Konkan

    Soil is non renewable natural resource which supports life on earth. It needs to be managed successfully to support sustainable development. It is growing in economic importance because of a broader environmental agenda.…

    • 3415 Words
    • 14 Pages
    Better Essays
    Read More
  • Good Essays

    Pastoral Farming
    • 918 Words
    • 3 Pages

    Pastoral Farming

    There are many factors that are taken into account to decide what type of farming should take place on a certain area of land including, topography, altitude, exposure, and rainfall. Soil plays a large role in determining how land will be used.Mollisol lands are typically described as semi-arid to semi- humid areas that are grassy. This is where most intensive cattle operations occur which produce beef and dairy. Although a majority of pastoral farming is conducted in Mollisol lands, pastoral farming can also be found in areas with soil made up of Entisol, Aridisol or Alfisol. Aside from soil order, pastoral farming is more likely to be found than arable farming in areas with steep slopes, cold strong winds and a wet…

    • 918 Words
    • 3 Pages
    Good Essays
    Read More
  • Good Essays

    Deforestation: Effects and Consequences
    • 302 Words
    • 2 Pages

    Deforestation: Effects and Consequences

    As the soil is eroded, it accelerates siltation in dams, rivers, and the coastal zone. The increased sedimentation harms downstream fisheries.…

    • 302 Words
    • 2 Pages
    Good Essays
    Read More

Related Topics