About The Book
This is comparatively a new book from our popular Author, who has turned the difficult subject of Geotech. Engineering into a simple one, by adopting his unmatachable skills and lucid language, as is the case with his other old publications, titled ' Irrigation Engineering and Hydraulic Structures', as well as ' The Environmental Engineering Vol. I & II'.
This book provides detailed description of the various properties and analysis of the behaviours of different types of Soils and Soil deposits, over which are rested the foundations of the different types of structures, like buildings, bridges, roads, machines, etc.
The design of the different types of foundations to be adopted to suit particular soil deposits and the proposed structure, without causing excess Differential or total Settlement or any other Failure of the underneath soil, to ensure the safety of the structure, has been explained in this volume in a simple language. The design of stable shapes for earthen embankments has been also exhaustively covered. The soid reinforcements and geotextiles, being used in modern days, have also been described in details with practical examples. The expansive and collapsible soils have also been described, giving details of special precautions required to betaken in providing structures on such soil deposits.
The text matter is further supported by more than 600 Objective Questions, including those from the Engineering Services, Civil Services (IAS), AMIE, and GATE Exams, giving Hints for solving difficult questions. The numerical questions of the past more than 10 years from these Competitive Examinations have also been solved, making the book highly useful for the Degree level engineering courses as well as for the Competitive Examinations.
Contents
Preface
Useful Conversions between Different Units
I. INTRODUCTION TO THE SUBJECT
II. SOILS, THEIR ORIGIN, Formation AND TYPES :
1. Definition of Soils
2. Origin and Formation of Soils
3. Types of Soils
4. Structures in Clay Minerals
5. Soil Map of India
III. CLASSIFICATION AND IDENTIFICATION OF Soils :
1. Need for Classification and its Possible Criteria
2. Classification of Soils on the Basis of Grain Size
3. Classification of Soils on the Basis of Plasticity
4. Determination of Atterberg's Limits (i.e. Liquid Limit and Plastic Limit)
5. Soil Classifications based on GRAIN Size and Plasticity
6. Field Identification Tests
IV. BASIC CHARACTERISTICS AND PROPERTIES OF SOILS :
1. Soil as a Three Phase System
2. Index Properties of Soils
3. Measurement of In-situ Density of a Soil Deposit in the Field
V. GEOSTATIC STRESSES IN SOILS AND PRINCIPLE OF EFFECTIVE STRESS :
1. Geostatic Stresses in Soils and Effective Stress Principle
2. Derivation of Effective Stress Principle
3. Effective Stress in a Partially Saturated Soil
4. Variation of Effective Stress with Shift in Ground Water-table
5. Variation of Effective Stress with Shift in Ground Surface
VI. Capillary Phenomena in Soils :
1. Soil Moisture and Capillary Water in Soils :
i. Capillary Rise in Glass Tubes
ii. Capillary Rise in Soils
iii. Capillary Pressure in Soils
iv. Capillary Syphoning
v. Estimation of Effective Pressure in Soils, Saturated with Capillary Water
VII. SOIL PERMEABILITY AND SEEPAGE THROUGH SOILS :
1. Definition of Permeability-An Engineering Property of Soil
2. Darcy's Law-One Dimensional Flow through Soils
3. Permeability Values for Different Soils
4. Factors Affecting Permeability
5. Laboratory Measurement of Permeability
6. Permeability of Stratified Soil Deposits
7. Aquifers and Wells
8. Pumping of Wells and Cone of Depression
9. Thiem's Equilibrium Formula for Unconfined as well as Confined Aquifers
10. Dupuit's Original Equilibrium Formulas
11. Partial Penetration of an Aquifer by a well
12. Spherical Flow in a Well
13. Interference Among Wells
14. Surface of Seepage and Free Surface Curves
15. Well Loss and Specific Capacity
16. Efficiency of a Well
17. Hydraulic Potential, Hydraulic Gradient and Seepage Pressure
18. Quick Sand Condition and Critical Hydraulic Gradient
19. Flow Nets
20. Failure of Hydraulic Structures Founded on Pervious Foundations
21. Bligh's Creep Theory for Seepage Flow
22. Khosla's Theory and Concept of Flow Nets
23. Seepage considerations in the Design of Earth Dams
VIII. COMPACTION OF SOILS :
1. Introduction and Definition
2. Role of Moisture in Compaction
3. Laboratory Determination of Optimum Moisture Content
4. Compaction of Soils in the Field
IX. COMPRESSION AND CONSOLIDATION Settlement :
1. Introduction
2. Definition of Compressibility and Its Importance
3. Theory as Applied to Compressibility Determination
4. Laboratory Test on Consolidometer
5. Analysing Consolidometer Test Results (For Compressibility) Consolidation
6. Consolidation Process
7. Mechanics of Consolidation
8. Terzaghi's Theory of Consolidation :
i. Application of Terzaghi's Consolidation Equation
ii. Determining Ct, from Consolidation Test Data
iii. Compression Ratios
X. STRESSES CAUSED BY External LOADS IN SOILS :
1. Introduction
2. Boussinesq Equations for Computing Stresses in a Soil Mass
3. Westergaard's Equations
4. Comparison of Boussinesq's and Westergaard's Equations
XI. Shear Strength of Soils :
1. Analysing Shear Failures
2. Shear Strength of Soils
3. Methods of Determining Shear Strengths of Soils
4. Skemptons Pore Pressure Parameters A & B
5. Shear Characteristics of Soils
XII. LATERAL EARTH PRESSURE EXERTED BY SOILS :
1. Rankine's and Coulomb's Earth Pressure Theories
2. Rankine's Theory
3. Earth Pressure at Rest
4. Extending Rankine's Theory to the Retaining Wall Designs
5. Coulomb's Wedge Theory
XIII. DESIGN OF EARTH RETAINING STRUCTURES :
1. Design of Gravity and Cantilever Rataining Walls
2. Design of Cantilever Sheet Pile Walls
3. Design of Anchored Sheet Pile Walls
4. Design of Timbering and Bracing for Open Cuts
XIV. Stability ANALYSIS OF SIDE SLOPES OF EARTHEN EMBANKMENTS :
1. Introduction
2. Stability of Infinite Slopes
3. Stability Analysis of Finite Slopes
4. Seepage Control through Embankments
5. Seepage Control through the Foundations
6. Design of Filters
7. Slope Protection
XV. LOAD BEARING CAPACITY OF SOILS UNDER SHALLOW AND DEEP FOOTINGS BEARING CAPACITY OF SHALLOW AND DEEP FOOTINGS :
1. Introduction
2. Ultimate Bearing Capacity of Continuous Footings
3. Ultimate Bearing Capacity of Square, Circular and Rectangular Shallow Footings
4. Factor of Safety to be applied to Ultimate Bearing Capacity to Determine Safe Load Bearing Capacity and Net Load Bearing Capacity
5. Effect of High Water-table on Ultimate Bearing Capacity
6. Effects of Eccentric and Inclined Loadings
7. Effects of Local Shear Failures
8. Skempton's Design of Shallow and Deep Footings in Cohesive Soils
9. Meyerhofs Bearing Capacity Equation for Footings (Both Shallow and Deep)
10. Hansen's Bearing Capacity Equation for Footings (Both Shallow and Deep)
11. BIS Bearing Capacity Equation for Footings (Both Shallow and Deep)
12. Failure of Base of an Excavation due to Heaving Proportioning of Footings
15.13 Considering Reduced Live Loads for Designing Footings in Clayey Soils
14. Proportioning of Strap Footings
15. Proportioning of Combined Footings (Rectangular as well as Trapezoidal) Settlements of Footings
16. Settlement Considering in the Design of Foundations
17. Plate Load Test
18. Standard Penetration Test (SPT)
19. Static Dutch Cone Test Raft Foundations
20. Raft Foundations on Sands and Clays
XVI. Load Carrying Capacity of Pile Foundations
1. Introduction to Deep Foundations
2. Types of Piles
3. Bearing Capacity of Piles (Individual Piles)
4. Bearing Capacity of Piles in Groups
5. Negative Friction on Piles
6. Empirical Formulas for Estimating Efficiency of a Pile Group
7. Settlement of Pile Groups
8. Pile Groups Subjected to Eccentric Vertical Loads
9. Laterally Loaded Piles
10. Load Tests on Cast Piles in the Field
XVII. Well and Caisson Foundations :
1. Introduction to Well Foundation
2. Shapes of Wells and Component Parts
3. Depth of Foundation Wells and Grip Length
4. Ultimate and Safe Bearing Capacity of a Foundation Well
5. Forces Acting on Foundation Well
6. Dimensioning and Designing the Component Parts of a Foundation Well
7. Sinking of Wells, Analysis of Well Foundations
8. Coefficient of Horizontal Soil Reaction
9. Stability Analysis of a Rectangular Foundation Well
10. Stability Analysis for Heavy Rectangular Wells, Drilled and Pneumatic Caissons
11. Drilled Caissons
12. Pneumatic Caissons
XVIII. Machine Foundations :
1. Introduction
2. Machine Foundation and its Types
3. Basic Terms and Definitions Connected with the Vibrating Systems and Foundations
4. Degrees of Freedom of a Pedastal (Block) Foundation of a Machine
5. General Criteria for the Design of the Machine Foundations
6. Use of Mass Spring System for the Analysis of Vibrating Foundation Systems
7. Equating Mass-Spring Analogy to the Machine Foundation System
8. Determination of the Natural Frequency of the Foundation Soil System
9. Design Criteria for the Design of Foundations of Reciprocating Machines, as per I.S. Code
10 Design Criteria for the Design of Foundations of Impact Type Machines as per I.S. Code
11. Vibration Isolation and Control
XIX. Design of Flexible and Rigid Pavements :
1. Introduction and Definition
2. Types of Pavements
3. Causes of Failure of Pavements
4. Factors Governing the Design of the Pavements, Design of Flexible Pavements
5. Structural Components of a Flexible Pavement
6. Stresses in Flexible Pavements and Estimating the Deformation of Subgrade (Boussinesq's Theory)
7. Burmisters Two Layer Analysis of Flexible Pavements
8. Computations of Equivalent Wheel and Axle Loads for the Design of Pavements
9. Design Methods and Techniques used for the Design of Flexible Pavements, Design of Rigid Pavements
10. Functions of a Base under a Rigid Pavement
11. Stresses in Rigid Pavements
12. Design of Rigid Pavements by PCA (Portland Cement Association) Charts
XX. Ground Improvement and Soil Stabilisation Techniques :
1. Introduction
2. Mechanical Stabilisation
3. Stabilisation of Compressible Surface Soil Layers by Pre-loading
4. Stabilisation of Compressible Surface Soil Layers by Sand Drain Method
5. Stabilisation of Soils by the Use of Admixtures
6. Soil Stabilisation by Injection of Suitable Grouts
7. Drainage or Dewatering
XXI. Reinforcing Soils and Use of Geotextiles and Ground Anchors :
1. Definition of Reinforced Soils
2. Advantages offered by Reinforced Earth Structures
3. Types of Geo-reinforcements or Soil-reinforcements Geotextiles
4. Types of Geotextiles
5. Functions of Geotextiles
6. Specifications for Geotextiles
7. Procurement and Testing of Geotextiles in India
8. Precautions in Transportation and Storage of Geotextiles, Ground or Soil Anchors
9. Definition, Uses and Types of Ground Anchores
10. Installation of Ground Anchors
11. Design of Soil Anchors
12. Design of Rock Anchors
XXII. Expansive and Collapsible Soils :
1. Definition of Expansive Soils
2. Variation of Soil Moisture (Water Content) in Expansive Soils with Depth and with Seasons
3. Important Technical Terms Related to Expansive Soils
4. Design of Foundations in Expansive Soils, Collapsible Soils
5. Definition and Introduction of Collapsible Soils
6. Mechanisms Causing Collapse Compression
7. Collapse Potential and Magnitude of Collapse Compression
8. Measures to be Adopted while Raising Structures on Collapsible Landfills
XXIII. Site Investigation and Sub Soil Exploration :
1. Introduction
2. Spacing and Depth of the Bore Holes
3. Methods of Exploration and Lifting of Soil Samples
4. Observations of the Ground Water Table
5. Bore Hole Logging
6. Indirect Geophysical Methods of Soil Exploration
XXIV. Chapterwise Multi Choice Objective Questions : Objective Questions on Ch. 1 to 23 Answers of the Objective Questions Hints for Solving Starred Questions
XXV. Objective Questions of the Engineering Services Exams (1993-2007)-Geotech Engg. Portion :
Questions with Answers and Hints for Solving Starred Questions
XXVI. Objective Questions of GATE Exams (1991—2008)-Geotech Engg. Portion
Questions With Answers and Hints for Solving Starred Questions
XVII. Conventional Questions of the Engineering Services Exams (1990-2007)-Geotech Engg.
Fully Solved Numerical Questions
XXVIII. Conventional Questions of the Civil Services (IAS) Exams., (1989-2007)-Geotech Engg.
XXIX. Conventional Questions of GATE Exams.
Fully Solved Numerical Questions
XXX. Laboratory Experiments in Soil Mechanics
1. To Determine the Moisture Content of a Given Sample of Soil by Oven
Drying Method
2. To Determine the Specific Gravity of a Given Soil Sample passing
4.75 mm I.S. Sieve
3. To Determine the Density and Unit wt. of a Soil Deposit in the Field by :
i. Collecting an Undisturbed Soil Sample from the Field by using a Core Cutter; and
ii. Collected a Disturbed (Excavated) Soil Sample from the Field by
using Sand Replacement Method
4. To Determine the Permeability (K) of a Given Soil by a Permeameter using :
i. Constant Head Method; and
ii. Falling Head Method
5. To Determine the Grain Size Analysis for a Coarse Grained Soil by Sieve Analysis (Mechanical Analysis)
6. To Determine the Grain Size Analysis for a Fine Grained Soil by Hydrometer Method
7. To Determine the Liquid Limit of a Given Fine Grained Soil
8. To Determine the Plastic Limit of a Given Fine Grained Soil
9. To Determine the Optimum Moisture Content (OMC) and Maximum Dry Density (Proctor's Test on BIS Mould with Light Compaction) or I.S. Heavy Compaction Test (Proctor's Modified Test with a BIS Mould)
10. To Determine the Undrained Shear Strength of Cohesive Soils by Uncon-fined Compression Test
11. To Determine the Shear Strength of a Soft Clay Soil by Vane Shear Test in the (a) Field, (6) Laboratory
12. To Determine the Shear Strength Parameters c and <)> for a Given Sandy Soil at a Given Water Content by Direct Shear Test (Shear Box Test)
13. To Perform the Triaxial Shear Test on the Given Soil to Determine the Shear Strength Parameter under Different Drainage Conditions
14. To Perform One Dimensional Consolidation Test Using a Fixed Ring Consolidoineter to Determine Consolidation Settlement and Related Coefficients
15. To Perform Standard Penetration Test (SPT) in the Field to Determine the Value1 of N for Estimating Relative Density (Consistency) and Other Properties of Sandy as well as Cohesive Soils, and also to Estimate the Net Bearing Capacity of the Ground for a Given Settlement for Installing a Footing of width B
16. To Pcform Plate Load Test in the Field on Ground Soil to Determine its Bearing Capacity for a Given Settlement and to Determine the Ultimate and Safe Bearing Capacity
17. To Perform the North Dacota Cone (NDC) Test to Determine the North Dacota Cone Bearing Value of a Natural Ground Surface for Designing the Thickness of a Flexible Pavement (i.e. a Bituminous Road)
18. To Perform California Bearing Ratio (CBR) Test to Determine the CBR Value for Designing the Thickness of Flexible Pavements (Bituminous Roads) for the Given Type of Traffic Intensity (Light, Medium or Heavy) by using CBR Design Curves