WITH EFFECT FROM THE ACADEMIC YEAR 2012 - 2013
CE 351
SOIL MECHANICS
Instruction 4 Periods per week
Duration of University Examination 3 Hours
University Examination 75 Marks
Sessional 25 Marks
UNIT-I
Origin & Classification of Soils - Soil as a pseudo-elastic three phase particulate medium.
Physical Properties of Soil: Weight ratios (Water content, Density, Unit weights, Specific Gravity); Volume ratios (void ratio, porosity, degree of saturation, relative density); Inter-relationships. Laboratory tests for determination of Index properties.
Classification and Identification of soils for general and Engineering purposes as per IS:1498-1970. Field identification of soils.
UNIT-II
Soil moisture states.
Capillarity in Soils: Surface tension and capillary rise in soil, Capillary tension, Capillary pressure. PF value
Permeability of Soils : Darcy’s law for flow through soils- validity of Darcy’s Law- Factors affecting permeability – Laboratory tests for determination of co-efficient of permeability (constant head, variable head permeability tests)- Field tests(Pumping in and pumping out tests)-Equivalent permeability of stratified soils.
Seepage in Soils: Seepage flow, seepage pressure – Flow nets- Locating phreatic line in a homogeneous earthen dam using Kogeny’s parabola – computation of seepage quantity.
Stress in Soils: Total effective and neutral stress
Quick Sand phenomena: Critical Hydraulic gradient, Remedial measures.
UNIT-III
Compaction Process: Compaction Mechanism; factors affecting compaction. Laboratory determination of compaction characteristics-standard and modified Proctor tests- IS Light and Heavy compaction tests; Field surface compaction : compaction equipment, procedure, quality control
Consolidation Process: Spring analogy - Void ratio and effective stress (e Vs logP) relationship – Terazaghi’s theory of one dimensional consolidation - assumptions and derivation of GDE – Computation of magnitude of settlement and time rate of settlement.
UNIT-IV
Shear Strength: Significance of Shear strength in soils – Mohr-Coulomb equation – shear parameters- Laboratory tests for determination of shear strength – Direct shear test, Tri-axial compression tests (UU, CU and CD), Un-confined compression test, Vane shear test. Factors affecting shear strength of cohesion-less and cohesive soils. Determination of elastic modulii.
UNIT-V
Earth Pressure: States of earth pressure-Active, passive, at rest condition; Rankine’s theory: computation of active and passive earth pressure in c-less and c-Ö soils; Coulomb’s Wedge theory; Rehbhan’s graphical solution; stability of earth retaining gravity wall.
Slope stability: Definition and classification of slopes-types of slope failures-Factors of safety with respect to cohesion, angle of shearing resistance, Height – Analysis of stability of slope using Swedish slip circle method and Taylor’s stability number.
Suggested Reading:
- 1.Scott, R.F., “Principles of Soil Mechanics”, Addison Wesley, Massauchusetts.
- 2.Lambe, T.W. and Whitman, R.V., “Soil Mechanics”, John Wiley & Sons Inc., NY,1969.
- 3.Venkatramaiah, C., “Geo-technical Engineering”, New Age Publishers, revised third edition, 2006.
- 4.Shashi K.Gulhati and Manoj Datta, “Geotechnical Engineering”, Tata Mc-Graw Hill, 2005.
- 5.Arora, K.R., “Soil Mechanics and Foundation Engineering”,
Standard Publishers Distributors revised and enlarged sixth edition, 2007.
- 6.Gopal Ranjan and A S Rao, "Basic and Applied Soil Mechanics",
Wiley. Eastern Limited, 1996.
- 7.Relevant IS Codes.