Soil Mechanics (PCCET402) Syllabus

Nature of soil and functional relationships: introduction to geotechnical engineering, soil types, major soil deposits of India, 3-phase system, basic soil properties (void ratio, porosity, degree of saturation, air content, water content, specific gravity, unit weight), relationships between basic soil properties, relative density. Determination of water content by oven drying, specific gravity using pycnometer and specific gravity bottle, field density by sand replacement method and core cutter method. Soil structure and effects on basic soil properties, basic structural units of clay minerals (introduction only).

Index properties: sieve analysis, hydrometer analysis (Stokes' law, calibration, corrections), gradation of soil, combined sieve and hydrometer analysis. Consistency: Atterberg limits and indices, plasticity charts, activity of soil, laboratory tests for liquid limit (Casagrande's apparatus and cone penetrometer), plastic limit and shrinkage limit, IS classification of soil. Permeability: Darcy's law, factors affecting permeability, constant head and variable head tests, average permeability of stratified deposits. Principle of effective stress: total/neutral/effective stress, pressure diagrams, quicksand condition, critical hydraulic gradient.

Stress distribution: Boussinesq's equations for vertical pressure due to point and line loads, vertical pressure due to UDL beneath strip and circular areas, vertical pressure due to loading on rectangular area and Fadum's chart. Approximate methods: equivalent point load method, 2:1 distribution method, pressure isobars and bulbs, distribution of contact pressure beneath footings. Compaction Tests: OMC and MDD, zero air voids line, IS light and heavy compaction, factors affecting compaction, field compaction methods, Proctor needle.

Consolidation: coefficient of compressibility and volume compressibility, e-log p curve, compression index, recompression index, pre-consolidation pressure, normally/over/under consolidated soils, Terzaghi's theory of one-dimensional consolidation, average degree of consolidation, time factor, coefficient of consolidation, laboratory consolidation test. Shear strength of soils: Mohr-Coulomb failure criterion, Mohr circle method, relationship between shear parameters and principal stresses, laboratory tests — triaxial compression test (UU, CU, CD), unconfined compression test, direct shear test, vane shear test.