Soil Mechanics
Course Objective:
This course is aimed at teaching the students the concepts of soil engineering, including the science and technology of soils and their application to problems in Civil engineering.
The course emphasizes the fundamentals and relevant principles of soil mechanics, gives an overall picture of the behaviour of soils and describes the nature of some of the soil problems encountered in Civil engineering.
 Introduction (1 hour)
 Preview of Geotechnical problems in civil Engineering and infrastructure Development.
 Historical development of soil mechanics.
 Soil formation and soil type.
 Solids Water –Air Relations and Index properties of soils (5 hours)
 Phase diagram
 Simple definitions and their relationships
 Index properties of soils
 Determinations of various index properties
 Soil Identifications and Classification (4 hours)
 Introduction
 Field Identification of soil
 Soil classificationTextural, ISSCS, MIT, BSCS, USCS and AASHTO soil classification system
 Application of soil classification system
 Soil Structure and Clay Minerals (2 hours)
 Introduction
 Clay minerals
 Clay particle interaction
 Soil structure and fabrics
 Soil Compaction (3 hours)
 Introduction
 Laboratory tests
 Factors affecting compaction
 Structure and Engineering behaviour of compacted cohesive soils
 Compaction specification and field control.
 Principle of Effective Stress, Capillarity and Permeability (5 hours)
 Introduction
 Principle of effective stress
 Physical meaning of effective stresses
 Capillarity in soils
 Permeability of soils
 Determinations of coefficient of permeability: Laboratory and field methods.
 Types of Head, Seepage forces and quick sand conditions.
 Seepage through Soils (4 hours)
 Introduction
 Two dimensional flow – Lap laces equation
 Flow nets
 Unconfined flow
 Seepage in Anisotropic soil condition
 Seepage through an earth dam on an impervious base
 Flow through non – homogeneous sections
 Prevention of Erosion Protective filters
 Vertical Stresses Below Applied Loads (4 hours)
 Introduction
 Boussinesq equation and Westergaard’s equation
 Vertical Stress Distribution Diagrams
 Vertical stress beneath loaded Areas
 New marks influence chart
 Approximate stress distribution methods for Loaded Areas.
 Compressibility of Soil (6 hours)
 Contact pressure and Settlement profile.
 Fundamentals of Consolidation
 One –Dimensional Laboratory consolidation Test
 Void Ratio – Pressure plots
 Normally consolidated and over consolidated clay
 Effect of Disturbance on Void Ratio –Pressure Relationship
 Calculation of Settlement from One – Dimensional Primary Consolidation
 Compression Index and Swell Index
 Secondary Consolidation Settlement
 Time Rate of Consolidation
 Coefficient of Consolidation
 Calculation of Consolidation Settlement under a Foundation
 Method of Accelerating Consolidation Settlement
 Shear Strength of Soil (6 hours)
 MohrCoulomb failure criterion
 Inclination of the Plane of Failure caused by Shear.
 Laboratory Tests For Determination of shear strength Parameters.
 Direct Shear Test
 Triaxial Shear TestGeneral
 Consolidated drained Triaxial Test
 Consolidated undrained Triaxial Test
 Unconsolidated undrained Triaxial Test
 Unconfined compression Test on Saturated clay.
 Stress Path
 Vane Shear Test
 Empirical Relations between undrained cohesion and effective overburden pressure.
 Shear strength of unsaturated Cohesive Soils.
 Shear Strength of Sands.
 Stability of Slopes (5 Hours)
 Introduction
 Infinite slopes and Translation slides
 Definition of factor of safety
 Finite slopes Forms of Slip surface
 Ø = 0 Analysis (Total stress Analysis)
 C – Ø Analysis – Method of Slices.
 Location of the most Critical Circles
 Friction Circle Method
 Taylors Stability Number
 Bishops method of Stability Analysis
 Use of Stability Coefficients
Tutorials:
 Introduction (0.5 hour)
 Solids Water –Air Relations and Index properties of soils (1.5 hour) : Numerical examples and derivation :: There can be tutorials for each subsection
 Soil Identifications and Classification (0.5 hour) :Practical examples :: There can be tutorials for each subsection
 Soil Structure and Clay Minerals (0.5 hour)
 Soil Compaction (1 hour) : Practical and numerical examples
 Principle of Effective Stress, Capillarity and Permeability (2 hours) : Practical example and numerical examples :: There can be tutorials for each subsection.
 Seepage through Soils (2 hours) : Numerical examples; Practical example :: There can be tutorials for each subsection.
 Vertical Stresses Below Applied Loads (1 hour) :Numerical examples type questions. :: There can be tutorials for each subsection.
 Compressibility of Soil (2 hours) :Numerical and Practical examples
 Shear Strength of Soil (2 hours) : Numerical and Practical examples :: There can be tutorials for each subsection
 Stability of Slopes (2 hours) : Numerical and Practical examples :: There can be tutorials for each subsection
Practical:
 Sieve analysis of coarse and fine grained soils.
 Determination of Atterberg limit of soils
 Determination of Insitu density by Sand replacement method and Core Cutter Method.
 Determination of OMC and maximum dry density
 Unconfined compression test
 Direct shear Test
 Constant head permeability Test
 UU Triaxial Test
References
 Terzaghi K and Peck.R. B. John Wiley “Soil mechanics in Engineering Practice”, 2nd Edition, New York, 1967
 Braja M. Das “Principles of Geotechnical Engineering” Fifth edition. Thomson/Brookscole
 Joseph E Bowles “Physical and Geological properties of soils”, , Mc Graw Hill Co. Ltd 2nd Edition 1984.
 Gopal Ranjan and ASR Rao “Basic and Applied soil mechanics “, second edition New Age International publishers,2000
 K. R. Arora “Soil mechanics and foundation Engineering” Standard Publisher Distribution 1997
 S.R. Kaniraj “Design Aids in Soil Mechanics and Foundation Engineering “, Tata Mc Graw Hill Education Limited, 2010
 V.N.S. Murthy “A Text Book of Soil Mechanics and Foundation Engineering in SI units“ UBS Publishers Distributors Ltd.Fourth edition 1993
 Dr. Sehgal “A text book of soil mechanics” S.B. CBS Publishers and distributors, New Delhi, 1988
Evaluation Scheme:
The questions will cover all the chapters of the syllabus. The evaluation scheme will be as indicated in the table below:
Chapters 
Hours 
Marks distribution* 
1 
1 
2 
2 
5 
8 
3 
4 
8 
4 
2 
4 
5 
3 
6 
6 
5 
10 
7 
4 
8 
8 
4 
8 
9 
6 
10 
10 
6 
10 
11 
5 
6 
Total 
45 
80 
*Note: There may be minor deviation in marks distribution.
