Phase Relationships in Soil Science
40 Questions
11 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

The ______ of soils ranges from approximately 2.3 to 2.8.

specific gravity

The lower range (2.3 to 2.5) are for ______ particles with traces of organic material.

silt

For most problems, Gs can be assumed, with little error, to be equal to ______.

2.7

Two types of container are used to determine the ______ for soil particles less than 4.75 mm.

<p>specific gravity</p> Signup and view all the answers

A soil is considered ______ if all voids are filled with water.

<p>saturated</p> Signup and view all the answers

The ______ of a soil is the ratio of the amount of water to the weight of the soil solids, expressed as a percentage.

<p>water content</p> Signup and view all the answers

One is a volumetric flask (at least 100mL) that is used for ______-grained soils.

<p>coarse</p> Signup and view all the answers

The ______ is the ratio of the volume of voids to the volume of solids.

<p>void ratio</p> Signup and view all the answers

The other is a 50-mL density bottle (stoppered bottle) that is used for ______-grained soils.

<p>fine</p> Signup and view all the answers

The ______ of the container and the dry soil is determined.

<p>mass</p> Signup and view all the answers

The ______ is the volume of soil per unit volume of solids.

<p>specific volume</p> Signup and view all the answers

The ______ is the ratio of the volume of voids to the total volume of the soil.

<p>porosity</p> Signup and view all the answers

The ratio of the volume of water to the volume of ______, often expressed as a percentage.

<p>voids</p> Signup and view all the answers

The weight of ______ is typically considered negligible in soil calculations.

<p>air</p> Signup and view all the answers

The ______ is the ratio of the weight of soil solids to the weight of water of equal volume.

<p>specific gravity</p> Signup and view all the answers

Coarse-grained soils typically have a maximum ______ of 48% and a minimum of 26%.

<p>porosity</p> Signup and view all the answers

Rd indicates how much soil is heavier than ______ per unit volume.

<p>water</p> Signup and view all the answers

Relative density indicates the degree of packing between the loosest and densest possible state of ______ soils.

<p>coarse-grained</p> Signup and view all the answers

The ______ limit is the water content at which the soil can no longer flow as a liquid.

<p>liquid</p> Signup and view all the answers

The boundary water content at the liquid limit is denoted by ______.

<p>LL</p> Signup and view all the answers

The ______ limit is the water content at which the soil changes from a plastic to a semi-solid state.

<p>plastic</p> Signup and view all the answers

The range of water contents over which the soil deforms plastically is known as the ______ index.

<p>plasticity</p> Signup and view all the answers

Swell factor is a ratio of the volume of excavated material to the volume of ______ material.

<p>in-situ</p> Signup and view all the answers

The physical and mechanical behavior of fine-grained soils is linked to four distinct states: solid, semi-solid, ______, and liquid.

<p>plastic</p> Signup and view all the answers

The ______ is useful for the determination of swelling and shrinking capacity of soils.

<p>shrinkage limit</p> Signup and view all the answers

The ______ limit is determined from an apparatus that consists of a semispherical brass cup repeatedly dropped onto a hard rubber base.

<p>liquid</p> Signup and view all the answers

The ______ limit is determined by rolling a small clay sample into threads and finding the water content at which threads of approximately 3mm diameter will just start to crumble.

<p>plastic</p> Signup and view all the answers

______ developed a method to describe the consistency of fine-grained soils with varying moisture content.

<p>Atterberg</p> Signup and view all the answers

The ______ index is linearly related to the amount of the clay fraction for soils with a particular mineralogy.

<p>plasticity</p> Signup and view all the answers

The ______ index is the ratio of the difference in water content between the natural water content of a soil and its plastic limit to its plasticity index.

<p>liquidity</p> Signup and view all the answers

The internal resistance of soil may come from inter-particle forces like ______ or adhesion.

<p>cohesion</p> Signup and view all the answers

The ______ is a measure of the consistency of a soil, defined as the ratio of the unconfined compressive strength of the soil at a given water content to the unconfined compressive strength of the soil at the liquid limit.

<p>consistency</p> Signup and view all the answers

The range of water content from the plastic limit to the shrinkage limit for which the soil behaves as a semisolid is called the ______ index.

<p>shrinkage</p> Signup and view all the answers

The equation for ______ describes the importance of the clay fractions on the plasticity index.

<p>activity</p> Signup and view all the answers

The ______ limit is defined as the moisture content at which the soil changes from a liquid to a plastic state.

<p>liquid</p> Signup and view all the answers

Terms such as stiff, hard, firm, plastic, soft, and very soft are often used to describe soil ______.

<p>consistency</p> Signup and view all the answers

The ______ limit is defined as the moisture content at which the soil changes from a plastic to a semisolid state.

<p>plastic</p> Signup and view all the answers

The ______ limit is defined as the moisture content at which the soil changes from a semisolid to a solid state.

<p>shrinkage</p> Signup and view all the answers

The volume of the oven-dried soil can be determined by using ______ to occupy the vacant spaces caused by shrinkage.

<p>mercury</p> Signup and view all the answers

Fine-grained soils can exist in four states: solid, ______, plastic, or liquid.

<p>semisolid</p> Signup and view all the answers

Study Notes

Phase Relationships in Soil

  • Soil is composed of solids, liquids, and gases
  • Solids may be minerals or organic matter
  • Voids are the spaces between soil particles
  • Water (porewater) is often the predominant liquid, and air is the predominant gas
  • Soil's physical parameters depend on the relative proportions of these phases
  • Variables include:
    • Vs = volume of solids
    • Vw = volume of water
    • Va = volume of air
    • V = total volume of soil
    • V = Vs + Vw + Va
    • e = Vv/Vs (void ratio)
    • n = Vv/V (porosity)
  • Water content (w) is the ratio of water weight (Ww) to soil weight (Ws):
    • w = (Ww/Ws) * 100%
  • Void ratio (e) is the ratio of void volume (Vv) to solid volume (Vs)
    • e = Vv/Vs
  • Specific volume (V') is the ratio of soil volume (V) to solid volume (Vs)
    • V' = V/Vs = 1 + e
  • Porosity (n) is the ratio of void volume (Vv) to total volume (V)
    • n = Vv/V = e/(1+e)
  • Specific gravity (Gs) is the ratio of the weight of soil solids (Ws) to the weight of an equal volume of water (Yw)
    • Gs = Ws / V * Yw

Weight-Volume Relationship

  • Water content (w):

    • The ratio of the amount of water (Ww) in the soil to the weight of soil solids(Ws) expressed as a percentage
  • Void ratio (e):

    • The ratio of the volume of voids to the volume of soil solids
  • Specific volume (V'):

    • the volume of soil per unit volume of solids:
  • Porosity (n):

    • The ratio of the volume of voids to the total volume
  • These properties are related through these expressions

    • e = Vv/Vs
    • n = Vv/V = e / (1 + e)
    • V' = V/Vs = 1 + e
  • The special cases of unit weights

  • Saturated unit weight

    • Ysat = (Gs + e)/(1 + e) * Yw
  • Dry unit weight

    • Yd = Gs / (1 + e) * Yw
    • Yd = Gyw(1-n)
  • Effective / Buoyant unit weight

    • Ye = Ysat - Yw

Specific Gravity

  • A measure of the density of soil solids relative to the density of water
  • Typical range for soil particles is 2.3 to 2.8, frequently approximated as 2.7
  • Typically used to determine soil properties

Degree of Saturation (S)

  • Degree of saturation (S) is a measure of the proportion of voids filled with water
    • S = Vw / Vv = Ww/(ws + wvw )
  • it's expressed as a percentage

Unit Weight (γ)

  • The weight of soil per unit volume
  • Bulk unit weight (γ): The weight of the soil (W) divided by its volume (V)
    • γ = W/V
  • Dry unit weight (γd): The weight of solids (Ws) divided by the total volume (V)
    • γd = Ws/V
  • Saturated unit weight (γsat): The total weight (W) including solids and water divided by the total volume (V)
    • γsat = (Gs + e * w) / (1 + e) * Yw

Special cases of Unit weights

  • Saturated unit weight: where the void spaces are filled with water
  • Dry unit weight: when the void spaces are filled with air only
  • Effective or Buoyant unit weight: The difference between a soil's saturated unit weight and the water unit weight

Relative Density (Dr)

  • An index that describes the soil's relative compactness with respect to the loosest and densest possible states. Dr values range from 0% for very loose and 100% for dense soil (Dr=(e max-e)/(emax - emin)
  • Typical values of unit weight

Void Ratio, Moisture Content, and Dry Unit Weight for Some Typical Soils in a Natural State

  • Table of typical values of soils
  • Loose and Dense uniform sand, loose and dense angular-grained silty sand, stiff clay, soft clay, loess, soft organic clay, and glacial till

Density Index (Id)

  • A measure of soil compactness relative to the maximum and minimum density
    • Id = (γd - γdmin) / (γdmax - γdmin)

Swell Factor (SF)

  • Ratio of the volume of excavated material to the volume of in-situ material (often expressed as a percentage)

Physical States of Fine-Grained Soil

  • Four states of fine-grained soil: solid, semisolid, plastic, and liquid
  • Transitions between these states are defined by specific water content thresholds

Atterberg Limits (LL, PL, SL)

  • Liquid limit (LL): The water content at which the soil transitions from liquid to plastic
  • Plastic limit (PL): The water content at which the soil transitions from plastic to semisolid
  • Shrinkage limit (SL): The water content at which the soil transitions from semisolid to solid

Activity

  • A parameter that describes the effect of clay minerals on plasticity (PI)
  • The equation for A is PI / (clay fraction %)

Liquidity Index (LI)

  • Ratio of the difference in water content between the in-situ water content and the plastic limit, to the plasticity index -LI = (w-PL)/PI

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Lesson 2 Geotech PDF

Description

Explore the complex relationships between solids, liquids, and gases in soil. This quiz covers crucial concepts like void ratio, porosity, and specific gravity. Understand how these parameters influence the physical properties of soil.

More Like This

Soil Science Essentials Quiz
12 questions
Soil Science Overview
33 questions
Soil Science Overview
10 questions

Soil Science Overview

JubilantUvarovite avatar
JubilantUvarovite
Soil Science: Soil Matrix and Phases
39 questions
Use Quizgecko on...
Browser
Browser