Basic Definitions and Simple Tests on Soil Mechanics

Introduction

This page discuss some of the basic definitions and simple tests used throughout the subject.

• The phase diagram is a simple, diagrammatic representation of a real soil.
• The phase diagram is also known as block diagram.
• A soil mass consists of solid particles, water and air, which are segregated and placed separately, known as three-phase system.
• A three-phase system becomes a two-phase system when the soil is absolutely dry (solids + air) or when the soil is fully saturated (solids + water).
• In phase diagram, volumes are represented on the left side, whereas weights are represented on the right side.

Volumetric Relationships

In total, there are fi ve volumetric relationships. These are as follows:

1. Void ratio (e):

• It is defi ned as the ratio of volume of voids to volume of solids.
• Range: e > 0
• e = Vv/Vs
• For some soils, it may have a value even greater than unity.
• The void ratio of coarse grained soils is, generally, smaller than that of a fi ne-grained soil.

2. Porosity (n):

• It is defined as the ratio of volume of voids to the total volume.
• n Vv/V
• Range: 0 < n < 1
• Also called ‘percentage voids’.
• Both porosity and void ratio are the measure of the degree of denseness (or looseness) of soil. Relationship between n and e:
• e = n /(n-1)
• n = e /(e+1)

3. Degree of saturation (Sr ):

• It is defined as the ratio of volume of water to the volume of voids, in soil.
• It is expressed as a percentage.
• Sr = Vw/Vv
• Range: 0 ≤ S ≤ 100%
• For dry soil, V w = 0 ⇒ S = 0
• For saturated soil, V w = V v ⇒ S = 100%

4. Percentage air voids (na ):

• It is defined as the ratio of volume of air to total volume, of soil.
• na=Va/V
• Range: 0 ≤ n a ≤ n

5. Air content (ac ):

• It is defined as the ratio of volume of air to the volume of voids, in soil.
• ac=Va/Vv
• Range: 0 ≤ a c ≤ 100%
• For dry soil, V a = V v ⇒ a c = 100%
• For saturated soil, V a = 0 ⇒ a c = 0
• Relationships between a c , n a , n and s:
• ac + S =1
• na= n*ac

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Soil Structure and Clay Mineralogy

Soil Structure

• Geometric arrangement of soil particles with respect to one another is known as soil structure.
• Depending upon the particle size and mode of formation, the following types are found.

Single Grained Structure

• Found in coarse grained soils, like gravel, sand.
• The major cause for formation is gravitational force. Here the surface forces are negligible.
• Under the influence of gravitational forces, the grains will assume a particle to particle contact referred to as single grained structure.

Single grained structure may be loose or dense as shown below.

• (a) Loosest state
• (b) Densest state

Honey-comb Structure

• It is possible for fine sands or silts.
• Both gravitational force and surface force are responsible.
• Such a structure can support loads, only under static conditions.
• Under vibrations and shocks, the structure collapses and large deformations take place.

Flocculated Structure

• This structure occurs in clays.
• Clay particles have a negative charge on surface and a positive charge on edges and flocculated structure occurs when there is an edge-to-face orientation.
• A flocculated structure is formed when there is a net attractive force between the particles.
• Soils with flocculent structure have a high void ratio and water content and, also have a low compressibility, a high permeability and high shear strength.

Dispersed Structure

• A dispersed develops in clays that have been reworked or remolded.
• Remoulding converts ‘edge-to-face’ orientation to ‘face- to-face’ orientation.
• Dispersed structure is formed when there is a net repulsive force between particles.
• Have low shear strength, high compressibility and low permeability.

Composite Structure

• A composite structure in the form of coarse grained skeleton or clay-matrix is formed when soil contains different types of soil particle

Clay Mineralogy

• Important clay minerals kaolinite, Illite, montmorillonite and halloysite, are present in clays.
• In coarse grained soils, like gravel, sand, rock minerals like quartz, feldspar, mica, etc., are present.

Kaolinite Mineral

• One molecule of kaolinite mineral is made of one silica sheet and one gibbsite sheet.
• Various such molecules are joined by hydrogen bonds.
• These show less change in volume due to changes in moisture content.
• Kaolinite is thus the least active of clay minerals.
• Example: China clay

Illite Mineral

• One molecule of Illite is made of two silica sheets and one gibbsite sheet, but in silica sheet, silicon atom is replaced by aluminum atom.
• Various such molecules are joined together by ionic bond (potassium ion).
• These shows medium swelling and shrinkage properties.
• Example: Alluvial soil.

Montmorillonite Mineral (Also Called ‘Smectite’)

• One molecule of montmorrilonite mineral is made of two silica sheets and one gibbsite sheet.
• Gibbsite sheet is sandwiched between silica sheets.
• Various such molecules are loosely bonded through water.
• These soils show high volume changes on moisture variation (i.e., large swelling and large shrinkage).
• Example: Black cotton soils, bentonite soil.

Diffuse Double Layer and Adsorbed Water

• Clay particles usually carry a negative charge on their surface.
• Because of net negative charge on the surface, the clay particles attract cations, such as potassium, calcium and sodium, from the moisture present in the soil to reach equilibrium.
• The layer extending from the clay particle surface to the limit of attraction is known as a diffuse double layer.
• The water held in the zone of the diffuse double layer is known as adsorbed water or oriented water.
• The plasticity characteristics of clay are due to the presence of adsorbed water.
• Clays using non-polar liquid, such as kerosene in place of water, does not show any plasticity characteristics.
• The thickness of adsorbed water layer is about 10–15 A°for colloids, but may be up to 200 A° for silts.

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Soil Mechanics - Study all topics

 Soil Mechanics Geo-technical

Engineering

Table of content

Chapter 1  Origin of Soils and Clay Mineralogy

• Introduction
• Soil formation and soil types
• Types of soil
• Commonly used soil designation
• Soil structure and clay mineralogy
• Soil structure
• Single Grained Structure
• Honey-comb Structure
• Flocculated Structure
• Dispersed Structure
• Composite Structure
• Clay Mineralogy
• Kaolinite Mineral other IMP link
• Illite Mineral
• Montmorillonite Mineral or Smectite
• Diffuse Double Layered Adsorbed Water

Chapter 2  Basic Definitions and Simple Tests

• Introduction
• Volumetric relationships
• Weight relationships
• Volume-weight relationships
• Specific gravity of solids (G)
• Mass specific gravity or apparent specific gravity (Gm )
• Important relationships
• Simple tests

Chapter 3  Index Properties and Soil Classification

• Introduction
• Index properties of soils
• Atterberg limits (or consistency limits)
• Soil classification

Chapter 4  Permeability

• Introduction
• Hydraulic head (h)
• Darcy’s law
• Seepage velocity (vs)
• Coefficient of absolute permeability (k )
• General expression for coefficient of permeability of soil
• Factors affecting permeability of soils
• Determination of coefficient of permeability

Chapter 5  Effective Stress and Seepage Pressure

• Introduction
• Definitions
• Importance of effective stress
• Effect of water table fluctuations on effective stress
• Capillary water
• Frost heave
• Frost boil
• Seepage pressure (P s )
• Quick Sand Condition
• Piping
• Prevention of piping failure
• Factor of safety against piping or quick sand

Chapter 6  Seepage Analysis, Stress Distribution and Compaction

• Introduction
• Seepage analysis
• Characteristic of flow net
• Uses of flow net
• Flow Net in an-isotropic soils
• Flow net in a non-homogeneous soil mass
• Flow net in a non-homogeneous soil
• Flow net in earth dams
• Stresses due to applied loads
• Compaction optimum wet and dry

Chapter 7  Consolidation

• Introduction
• Compressibility
• Consolidation
• Compaction
• Stages of consolidation
• Terzaghi’s spring analogy for primary consolidation
• Basic definitions
• Consolidation settlement (Sf )
• Consolidation of undisturbed specimen
• Over-consolidation ratio (OCR)
• Terzaghi’s theory of consolidation
• Differential equation of consolidation
• Degree of consolidation (U)
• Isochrones
• Determination of coefficient of consolidation
• Consolidation test
• Determination of void ratio at load increment
• Immediate settlement (Si )

Chapter 8  Shear Strength

• Introduction
• Definition
• Important points on mohr’s circle
• Strength theories for soils
• Coulomb envelopes for pure sand and for pure clay
• Types of shear tests based on drainage conditions
• Laboratory tests 
• Field tests
• Sensitivity of Soil
• Pore pressure parameters
• Liquefaction of sands

Chapter 9  Earth Pressure Theories

• Introduction
• Definition of lateral earth pressure
• Types of lateral earth pressure
• Rankine’s earth pressure theory
• Coulomb’s wedge theory
• Rehbann’s method

Chapter 10 Stability of Slopes

• Introduction
• Types of slopes
• Type of slope failure
• Different definitions of factor of safety (F s )
• Stability of an infinite slope of cohesion-less soils
• Stability analysis of an infinite slope of cohesive soils
• Finite slopes
• Swedish circle method or method of slices
• Location of most critical circle
• Effective stress analysis
• Bishop’s method
• Friction circle method
• Taylor’s method

Chapter 11 Bearing Capacity

• Introduction
• Types of foundation
• Definitions
• Criteria for determination of bearing capacity
• Factors affecting bearing capacity
• Compensated raft or floating raft
• Methods of determination of bearing capacity
• Types of shear failure
• Effect of water table on bearing capacity
• Meyerhaf’s bearing capacity theory
• Skempton’s analysis for cohesive soils
• Settlement analysis
• Plate load test

Chapter 12 Pile Foundation

• Introduction
• Necessity of pile foundations
• Classification of piles
• Pile driving
• Load carrying capacity of piles
• Negative skin friction
• Dynamic formulae
• Pile load test
• Group action of piles
• Efficiency of pile group ( h g )
• Group capacity of piles (Q g )
• Under reamed piles in clay

Chapter 13 Soil Exploration

• Introduction
• Objectives of soil exploration
• Methods of soil exploration
• Types of soil samples
• Corrections for standard penetration number
• Cone penetration tests
• Static cone penetration test
• Dynamic cone test
• In-situ tests using a pressure meter
• Geophysical methods

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Qualities of Good Timber - Building Material - Civil Engineering

Qualities of Good Timber

Following are the characteristics or qualities of a good timber:

1. Appearance quality of Good Timber: 

• A freshly cut surface of timber should exhibit hard and shining appearance.

2. Colour quality of Good Timber : 

• The colour of timber should preferably be dark. The light colour usually indicates timber with low strength.

3. Defects quality of Good Timber: 

• A good timber should be free from serious defects, e.g., dead knots, fl aws, shakes, etc.

4. Durability quality of Good Timber:

• A good timber should be durable. It should be capable of resisting the actions of fungi insects, chemicals, physical agencies and mechanical agencies.

5. Elasticity quality of Good Timber: 

• This is the property by which timber returns to its original shape when load causing its deformation is removed. This is a sought after property of timber when it is used for making bow, carriage shafts, sport goods, etc.

6. Fibres quality of Good Timber: 

• The timber should have straight fibres.

7. Fire resistance quality of Good Timber: 

• The timber is a bad conductor of heat. A dense wood off ers good resistance to the fire and it requires sufficient heat to cause a flame.

8. Hardness quality of Good Timber: 

• A good timber should be hard, i.e., it should off er resistance when penetrated by another body.

9. Mechanical wear quality of Good Timber: 

• A good timber should not deteriorate easily due to mechanical wear or abrasion.

10. Shape quality of Good Timber: 

• A good timber should be capable of retaining its shape during conversion or seasoning. It should not bow or warp or split.

11. Smell quality of Good Timber: 

• A good timber should have sweet smell. An unpleasant smell indicates a decayed timber.

12. Sound quality of Good Timber: 

• A good timber should give out a clear ringing sound when struck. A dull heavy sound, when struck, indicates a decayed timber. 
• The velocity of sound in wood varies between 2–17 times greater than that in air and hence, the wood may be considered high in sound transmission.

13. Strength quality of Good Timber: 

• A good timber should be strong for working as structural member, such as joist, beam, rafter, etc.

14. Structure quality of Good Timber: 

• It should be uniform. The fibres should be firmly added. 
• The medullary rays should be hard and compact.

15. Toughness quality of Good Timber: 

• A good timber should be tough, 
• i.e., it should be capable of offering resistance to the shocks caused due to vibrations.

16. Water permeability quality of Good Timber: 

• A good timber should have low water permeability which is measured by the quantity of water filtered through a unit surface area of specimen of wood.

17. Weathering effects quality of Good Timber: 

• A good timber should be able to reasonably withstand the weathering effects. 
• When timber is exposed to weather, its colour normally fades and slowly turns grey.

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Natural Seasoning and Artificial Seasoning of Timber

Differences between Natural Seasoning and Artificial Seasoning

Natural Seasoning 

• It is difficult to reduce the moisture content below 15–18%
• It is simple and economical.
• It is more liable to attack of insects and fungi.
• It requires more space for stacking.
• It is a slow process.
• It gives stronger timber.

Artificial Seasoning

• The moisture content can be reduced to any desired level.
• It gives weaker timber.
• It is a quick process.
• It requires less space for stacking.
• It is less liable to attack of fungi.
• It is expensive and highly technical.

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Building Materials - All content topic oriented

 Table of Contents

Chapter 1: Concrete and Its Constituents

• Cement
• Aggregates
• Admixtures
• Concrete

Chapter 2: Steel 

• Introduction
• Structural steel and metal
• Uses of steel
• Properties: Mild steel vs hard steel
• Defects in steel
• Steel manufacturing processes
• Mechanical treatment of steel
• Market form of steel and irons
• Different form of irons

Chapter 3: Bricks and Mortar 

• Bricks 
• Mortar and Limes
• Masonry and Tunnels

Chapter 4: Timber 

• Timber
• Structure of a tree
• Processing of timber
• Difference b/w natural and artificial seasoning
• Seasoning and preservation of timber
• Defects in timber
• Qualities of good timber
• MCQ for Timber - 1,2;
• Quick revision of timber

Chapter 5: Bitumen  

• Introduction

Chapter 6: Paint

• Introduction
• MCQ - 1 2 3 4 5 

Chapter 7: Stones and Glasses

• Stones
• Glasses

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Civil Engineering Subjects

Civil Engineering Subjects list

Click on following topics and get all topics and chapters in one places

Building Materials

Fluid Mechanics

Solid Mechanics

Soil Mechanics

Irrigation

Water Resource Engineering

Environmental Engineering

Structure Analysis

Structural Engineering Design

Transportation Engineering

Surveying

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CSEB JE/AE CIVIL QUESTION PAPERS 2018 for CSPHCL Recruitment 2021

Cseb JE/AE civil Engineering Question Paper 2018:

CSPHCL JE/AE CIVIL Recruitment 2021 - Previous Year Papers

Download CSPHCL JE/AE CIVIL Previous Year Papers PDFs for Free Here!

• Chhattisgarh State Power Holding Company Limited takes the responsibility of selecting candidates for the post of Junior Engineer. The candidates who have completed their education and are ready with the eligibility criteria will be able to apply for the CSPHCL JE/AE CIVIL. 
• The candidates will be selected for the CSPHCL JE/AE CIVIL exam on the basis of their performance in the Computer-based test and document verification. The aspirants of the CSPHCL JE/AE CIVIL exam must have started their preparations and if not then do not worry. 
• We have provided a few CSPHCL JE/AE CIVIL previous year papers for the candidates. The CSPHCL JE/AE CIVIL previous year papers will be helpful to the candidates as they get various different questions to practice and get an idea of the type of questions asked in the CSPHCL JE/AE CIVIL exam. By practicing with a variety of question sets, candidates will gain knowledge of the different types of questions that will be asked on the exam, boost their confidence, improve their accuracy, and speed up their response time. You can download various CSPHCL JE/AE CIVIL Previous Year Papers from the links below.

• Dear Aspirants!!!! 
• Here we provide CSPHCL JE/AE Engineer Previous Papers in PDF Format. So, applicants who want to make their preparation easy can download and practice CSPHCL JE/AE Engineer Previous Papers. Also, we provide CSPHCL JE/AE Engineer Syllabus PDF along with CSPHCL JE/AE Engineer Exam Pattern 2020-21 on this page for free cost. Also, Get details Of CSPHCL JE/AE Engineer Recruitment 2021 in the following sections. Moreover, aspirants can visit the official site of CSPHCL by scrolling down this page.

• CSPHCL JE/AE CIVIL  Previous Year Papers: All Papers Available Here!
• The ability to manage your time is the most important skill to have during your preparations. Candidates must practice and gain a solid understanding of the various types of questions in order to save the most time possible. 
• You can complete one paper per day to get an idea of your own level of preparation. You can also divide the papers into sections and work on each one separately.
•  We've put together a number of question sets to help you save time and prepare for the CSPHCL JE/AE CIVIL Previous Year Papers. The CSPHCL JE/AE CIVIL previous year’s papers can be found by clicking on the links below.

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• Benefits of Solving CSPHCL JE/AE CIVIL Previous Year Papers

• Candidates studying for the CSPHCL JE/AE CIVIL exam should go over the previous year's papers. As candidates solve CSPHCL JE/AE CIVIL previous year papers, their accuracy and time management skills, as well as their approach to various types of work, will improve, allowing them to better comprehend their concepts.

• Candidates will be able to understand the CSPHCL JE/AE CIVIL Syllabus and exam pattern by practicing on the CSPHCL JE/AE CIVIL Previous Year Papers. It is advantageous to understand sectional weighting, the marking scheme, the question pattern, repeated questions, and unique questions, among other things.

• It improves the speed and accuracy of the candidates. You will become more familiar with CSPHCL JE/AE CIVIL question papers as you solve more of them. As a result, you'll have a better grasp of the questions and be able to respond to them more quickly and accurately. By reviewing CSPHCL JE/AE CIVIL’s previous year papers, candidates can assess their own level of preparation.

• Hopefully, the above article regarding CSPHCL JE/AE CIVIL’s previous year papers has been informative. If you wish to score higher marks and enhance the chances of qualifying for the CSPHCL JE/AE CIVIL exam, then download the previous year papers we wish you good luck.

Get Complete Details Of CSPHCL JE Recruitment 2021 @ www.cspc.co.in

Name Of The Organisation	Chhattisgarh State Power Holding Company Limited
Post Name	JUNIOR Engineer (Electrical, Mechanical, Civil)
Total No Of CSPHCL Assistant Engineer Vacancies	28 Posts only for CIVIL engineering
CSPHCL Application Mode	Online
Starting Date To Apply Online For CSPHCL Assistant Engineer Recruitment 2021	29-09-2021
Last Date To Fill Online For CSPHCL JE Vacancies 2021	18-10-2021
CSPHCL JUnior Engineer Exam Date 2021	5 to 14 january 2022
CSPHCLJE Selection Process	Computer-based Test only
CSPHCL JE Job Location	Chattisgarh
Category	Previous Papers
CSPHCL Official Website NOTICE Advertisement	www.cspc.co.in click here CLick here

In the above tabular form, we provide detailed information on CSPHCL Assistant Engineer Vacancies 2021. Individuals

CSPHCL JE/AE Previous Year Papers FAQs

Do we only need to practice from the CSPHCL JE/AE previous year papers for the exam?

• Likewise, if you practice you will surely crack job in CSPHCL Junior Engineer Exam 2021. Also, practice CSPHCL Assistant Engineer Previous Papers as soon as completion of the application process.

What are the topics included in the CSPHCL JE/AE exam syllabus?

• All topic related to civill engineering subjects asked in other exams.

From where do we download the CSPHCL JE/AE previous year papers?

• Just click here and download your papers

What is the CSPHCL JE/AE exam pattern

Exam Type	Parts	Total Subjects	Number Of Questions	Time Duration
Multiple Choice Test	Part I	Professional Subjects	80	2 Hours
Part II	General Awareness & Reasoning	20
Total	100 Q

• CSPHCL JE Exam is Multiple Choice Based Test

 Similarly, you can download CSPHCL Assistant Engineer Syllabus and CSPHCL Assistant Engineer Exam Pattern 2020-21 for free cost.

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