History of soil mechanics, Definition, origin andformation of soil. Phase Diagram, Voids ratio, Porosity, Percentage AirVoids, Air content, Degree of saturation, Water content, Specific Gravity ofsoil solids and soil mass, Densities and Unit weights - Bulk, Dry, Saturated &Submerged and their inter relationships.
Index Properties of soil- Water content , Specific Gravity, Particle sizedistribution, Relative Density, Consistency limits and indices, in-situ density,Activity of Clay, Laboratory methods of determination of index properties ofsoil: Water content (Oven Drying method & Rapid Moisture method),Specific gravity of soil solids (Pycnometer and density bottle method),Particle size distribution (Sieve analysis and Hydrometer analysis only),Liquid Limit- (Casagrande and Cone penetration methods), Plastic limit andshrinkage limit.
CLASSIFICATION OF SOILS: Purpose of soil classification, Particle sizeclassification – MIT classification and IS classification, Texturalclassification. IS classification - Plasticity chart and its importance, Fieldidentification of soils.CLAY MINERALOGY AND SOIL STUCTURE: Single grained, honeycombed, flocculent and dispersed structures, Valence bonds, Soil-Watersystem, Electrical diffuse double layer, adsorbed water, base-exchangecapacity, Isomorphous substitution. Common clay minerals in soil and theirstructures- Kaolinite, Illite and Montmorillonite.
Darcy’s law- assumption andvalidity, coefficient of permeability and its determination (laboratory andfield), factors affecting permeability, permeability of stratified soils, Seepage velocity, Superficial velocity and coefficient of percolation, quick sandphenomena, Capillary Phenomena.
Concept of shear strength, Mohr-coulombtheory, conventional and modified failure envelops, Effective stress concept-total stress, effective stress and Neutral stress, Concept of pore pressure,Total and effective shear strength parameters, factors affecting shear strengthof soils, Sensitivity and Thixotropy of clay.
Definition, Principle of compaction, Standardand Modified proctor’s compaction tests, factors affecting compaction, effectof compaction on soil properties, Field compaction control – compactiveeffort & method, lift thickness and number of passes, Proctor’s needle,Compacting equipment.
Definition, Mass-spring analogy, Terzaghi’sone dimensional consolidation theory-assumption and limitations (noderivation), Normally consolidated, under consolidated and over consolidatedsoils, pre-consolidation pressure and its determination by Casagrande’smethod. Consolidation characteristics of soil (Cc, av, mv and Cv).
Measurement of shear parameters- Directshear test, unconfined compression test, Triaxial compression test and vaneshear test, Test under different drainage conditions.Laboratory one dimensional consolidation test, Determination ofconsolidation characteristics of soils-compression index and coefficient ofconsolidation (square root of time fitting method, logarithmic time fittingmethod).