Syllabus - Geotechnical Engg (CE701)

INTRODUCTION, INDEX PROPERTIES AND CLASSIFICATION OF SOILS

Definition and scope of soil mechanics, Origin of soil, formation of soil, clay minerals, Soil structure. 3-phase soil system, Basic terminology, and their relations, index properties of soil - Water content, Field density, Specific gravity, Grain size distribution by sieve and hydrometer analysis, Relative density, Atterberg limits and their determination, Various indices -Flow-Index, Plasticity Index, Toughness Index, Liquidity Index, Activity Ratio. Different Systems of Soil Classification - Particle Size, Textural, Unified, HRB and IS classification. Field identification of soils

PERMEABILITY, EFFECTIVE STRESS AND SEEPAGE THROUGH SOILS

Types of soil water, Capillarity in soils, Flow of water through soils, Darcy’s Law, permeability, Factors affecting permeability, Laboratory & field tests for determination of coefficient of permeability, Permeability of layered soils. Seepage pressure, total, Neutral and effective stress, Upward and downward seepage through soils, , Flow nets: characteristics, Methods of construction of flow net, Application of flow net, Quick condition, Laplace Equation for two –dimensional flow, Seepage through anisotropic soil and non-homogenous soil, Seepage through earth dam.

STRESS DISTRIBUTION IN SOILS AND COMPACTION

Boussinesq’s and Westergard’s theories for point load, Uniformly loaded circular and rectangular areas, Pressure bulb, Variation of vertical stress under point load along vertical and horizontal plane, Newmark’s influence chart for irregular areas. Contact pressure distribution in sands and clays. Mechanism importance of compaction, Standard Proctor compaction test, Modified compaction test Factors affecting compaction, Effects of compaction on soil properties, Field compaction equipment and compaction quality control.

CONSOLIDATION

Types of compressibility, Spring analogy, Immediate settlement, Primary consolidation and secondary consolidation, Stress history of clay, e-p and e-log p curves, Normally consolidated soil, Over consolidated soil and under consolidated soil, Pre-consolidation pressure and its determination, Consolidation test, Terzaghi’s 1-D consolidation theory, Coefficient of consolidation, Square root time and Logarithm of time fitting methods, Computation of total settlement.

SHEAR STRENGTH & STABILIZATION OF SOILS

SHEAR STRENGTH: Definition and importance of shear strength, Mohr and coulomb failure theories, Mohr’s Stress Circles, Measurement of shear strength-Different types of Shear Test namely, Direct Shear Test, Unconfined Compression Test, Tri Axial Compression Test & Vane Shear Test for strength parameters, Strength tests based on drainage conditions, Measurement of pore pressure, Pore pressure parameters, Strength envelops, shear strength of sands, Critical void ratio, Liquefaction, Shear strength of clays. Factors affecting shear strength of granular soils and cohesive soils. STABILIZATION OF SOIL: Introduction, Mechanical stabilization, Cement stabilization, Lime stabilization, Bituminous stabilization, Chemical stabilization, Thermal stabilization, Electrical stabilization, Stabilization by grouting, Use of geo-synthetic materials, Types, Functions and applications of geo-synthetics, Reinforced earth structures-components and construction.