Soil Science Chapter 1

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Questions and Answers

What is the term used to describe soil transported by wind?

Lacustrine soil

Aeolian soil (correct)

Alluvial soil

Marine soil

What is the Latin word from which the term 'soil' is derived?

Solia

Sonum

Soila

Solium (correct)

What type of soil is formed through the deposition of soil particles by river water?

Marine soil

Aeolian soil

Alluvial soil (correct)

Glacial soil

What is the term used to describe the removal of soil from rivulets by concentrated overland flow?

Gully erosion Signup and view all the answers

What would be the effect of planting trees on soil erosion?

Decrease soil erosion Signup and view all the answers

What type of soil is formed through the deposition of soil particles by glaciers?

Glacial soil Signup and view all the answers

What type of soil is characterized by its strength depending on friction between particles?

Cohesionless soil Signup and view all the answers

What is the term used to describe soil deposited in lakes?

Lacustrine soil Signup and view all the answers

What is the name of the soil that is transported by flowing water?

Alluvial soil Signup and view all the answers

What is soil erosion?

The detachment, transport, and deposition of soil particles on land surface Signup and view all the answers

What is the term used to describe soil deposited in the sea?

Marine soil Signup and view all the answers

What is humidity?

The water vapour in the air Signup and view all the answers

Which type of soil is known for being most fertile?

Alluvial soil Signup and view all the answers

What is the term used to describe the settling and distribution of particles in the soil mass?

Fabric Signup and view all the answers

Who is known as the Father of Soil Mechanics?

Karl Terzaghi Signup and view all the answers

What is an incorrect process of physical disintegration in regards to the formation of soils?

Plantation of trees and plants Signup and view all the answers

Why is sand not ideal for the preparation of mortar?

It is soft Signup and view all the answers

What happens to the compression index if the liquid limit is increased?

It decreases Signup and view all the answers

What type of soil is characterized by being sticky, plastic, and dark colored?

Clay soil Signup and view all the answers

What is the property of sand that is ideal for construction?

It is well graded Signup and view all the answers

What is the correct formula for compression index?

cc = 0.007 (wL - 10) Signup and view all the answers

What is absolute humidity?

It is expressed in kg/m3 Signup and view all the answers

What is the term used to describe the arrangement of particles in the soil mass?

Fabric Signup and view all the answers

What is the primary method of preventing soil erosion?

Plantation of trees and plants Signup and view all the answers

What is the term used to describe the moisture absorbed by a dry soil from the atmosphere?

Hygroscopic moisture Signup and view all the answers

What is the characteristic of Gumbo soil?

It is a black colored soil, which is sticky and highly plastic in nature Signup and view all the answers

Why is Black cotton soil unsuitable for foundations?

Due to its tendency to shrink and swell Signup and view all the answers

What is the coefficient of softening of clay?

Zero Signup and view all the answers

What is the characteristic of Peat soil?

It is a fibrous aggregate with decomposed fragments of vegetable matter Signup and view all the answers

What is the effect of climatic changes on Loess soil?

It causes vertical swelling and horizontal shrinkage Signup and view all the answers

What is the characteristic of Loess soil in terms of permeability?

It has lower permeability in the horizontal direction Signup and view all the answers

What is Marl soil composed of?

Clay, loam, and calcareous sands Signup and view all the answers

What is the characteristic of Black cotton soil?

Low density and high compressibility Signup and view all the answers

What is the suitable foundation for a shallow layer of Black cotton soil?

Remove the layer of soil Signup and view all the answers

What is the characteristic of a soil sample with complete saturation?

Pore water pressure is positive Signup and view all the answers

What is the mineral responsible for the low shearing strength of Black cotton soil?

Montmorillonite Signup and view all the answers

Which of the following statements is incorrect about Black cotton soil?

It has low shrinkage and swelling characteristics Signup and view all the answers

What is the suitable foundation for a deep layer of Black cotton soil?

Uncleared-reamed piles Signup and view all the answers

What is the characteristic of Loess soil?

Uniformly graded silt deposit Signup and view all the answers

What type of system is a partially saturated soil sample?

Three-phase system Signup and view all the answers

Study Notes

Origin of Soil and Soil Water Relationship

Soil is derived from the Latin word "Solium", which means the upper layer of the earth that may be dug or plowed, specifically, the loose surface material of the earth in which plants grow.

Types of Soil

Aeolian soil: soil transported by wind, like sand-dunes and loess.
Alluvial soil: soil deposited by rivers or running water, often found at river banks.
Marine soil: soil deposited by sea water.
Lacustrine soil: soil deposited by still water, like lakes.
Glacial soil: soil deposited by ice (till or drift).

Soil Erosion and Prevention

Soil erosion: the detachment, transport, and deposition of soil particles on land surfaces.
Planting trees and plants can reduce soil erosion by preventing sediment and soil settlement.
Methods for preventing and reducing soil erosion include plantation of trees and plants, and controlling excessive grazing.

Soil Mechanics

Father of Soil Mechanics: Dr. Karl Terzaghi, who coined the term "Soil Mechanics" in 1925.
Soil mechanics involves the study of the physical properties and behavior of soils.

Physical Disintegration of Soil

Physical disintegration of soil: the breakdown of soil particles into smaller fragments.
Incorrect process of physical disintegration: spreading of roots of plants.

Soil Properties

Cohesionless soil: soil whose strength depends on friction between particles, like sand or gravel.
Fabric of soil: the geometrical arrangement of soil particles, including void spaces.
Fertile soil: soil with adequate proportions of potash, phosphoric acid, and lime, ideal for plant growth, like alluvial soil.

Soil Types

Gumbo: a black, sticky, plastic clay soil with small amounts of sand or organic material.
Marl: a combination of clay, loam, and calcareous sands.
Peat: a fibrous aggregate of decomposed vegetable matter.
Loess: a uniformly graded silt deposit made by wind, with low density and high compressibility.

Soil Behavior

Hygroscopic moisture: the trace moisture absorbed by dry soil from the atmosphere, held as a thin film on soil particles.
Coefficient of softening for clay is zero, indicating that the compressive strength of saturated clay is zero.

Soil Applications

Black cotton soil is unsuitable for foundations due to its high shrinkage and swelling characteristics, and low shearing strength.
Raft foundations or uncler-reamed piles are used for structures on black cotton soil to counter its settling and swelling behavior.

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Description

This quiz covers the basics of soil science, including the origin of soil and soil water relationships.