Geotechnical Engineering

Unit 1

Shear strength of soils: Mohr – Coulomb Failure theories – Types of laboratory strengthtests – strength tests based on drainage conditions – Shear strength of sands – Critical Void Ratio – Liquefaction - shear strength of clays.

Soil Exploration: Need – Methods of soil exploration – Boring and Sampling methods – Field tests – Penetration Tests – Plate load test – Pressure meter – Planning of programme and preparation of soil investigation report.

Unit 2

Shallow Foundations: Types - choice of foundation – Location of depth – Safe Bearing Capacity – Terzaghi, Meyerhof, Skempton and IS Methods.

Safe bearing pressure based on N-value – allowable bearing pressure; safe bearing capacity and settlement from plate load test – allowable settlements of structures – Settlement Analysis.

Pile Foundation: Types of piles – Load carrying capacity of piles based on static pile formulae – Dynamic pile formulae – Pile load tests - Load carrying capacity of pile groups in sands and clays – Settlement of pile groups.

Well Foundations: Types – Components of well foundation – functions and design. Design Criteria – Sinking of wells – Tilts and shifts.

Unit 3

Earth Slope Stability: Infinite and finite earth slopes – types of failures – factor of safety of infinite slopes – stability analysis by Swedish arc method, standard method of slices, Bishop’s Simplified method – Taylor’s Stability Number.

Earth Pressure Theories: Rankine’s theory of earth pressure – Earth pressure in layered soils – Coulomb’s earth pressure theory – Culmann’s graphical method.

Retaining Walls: Types of retaining walls – stability of retaining walls.