6CE2A: GEOTECHNICAL ENGINEERING – II (L-3, T-1)

  Units    Contents of the subjects
I
Stresses in Soil under surface loading: Bossinesq’s and Westergaard’s analysis for vertical pressure and its distribution in a soil mass. Vertical stresses due to concentrated loads, Horizontal and shear stresses due to concentrated loads. Isobar diagram, Vertical stress distribution on a horizontal plane. Influence diagram. Vertical stresses at point under line load and strip load. Vertical stresses at a point under circular and rectangular loaded area. Approximate methods of obtaining vertical pressure due to surface loading. Newmark’s chart, Fensk’s Chart. Pressure bulb and its significance in Foundation exploration. Contact pressure below foundations.
II
Compressibility and Consolidation: Introduction to consolidation, comparison of compaction and consolidation, Spring Analogy Terzaghis one dimensional consolidation theory, Degree of consolidation, consolidation test, Compressibility parameters, co-efficient of consolidation. Preconsolidation pressure and its determination. Normally, Over and Under consolidated soils. Methods of computation of Settlement and its rate. Coefficient of consolidation for layered soil. Total and differential Settlement.
III

Stability of Slopes: Classifications of slopes, Stability analysis of infinite slopes. Stability analysis of finite slopes by Swedish and Friction circle method. Stability analysis by Taylor’s stability number, Taylor stability number curves. Stability of slopes of earthen embankments under sudden draw down, steady seepage and during construction. Bishop’s method of stability analysis.

IV
Earth Pressure: Active, passive and earth pressure at rest. Rankine’s and Coulomb’s theories of earth pressure. Rebhann’s and Culman’s graphical methods for active earth pressure for vertical and inclined back retaining walls, horizontal and inclined cohesion less back fill. Earth pressure on cantilever sheet piles Stability analysis of retaining walls.
V
Bearing Capacity of Soils: Terminology related to bearing capacity, Common types of foundations. Terzaghi and Meyehoff’s theory for bearing capacity. Rankine’s method for minimum depth of foundation. Skempton’s method. Effect of eccentricity and water table on bearing capacity. IS code method, Plate load and penetration tests for determining bearing capacity. Introduction to pile, well and machine Foundations.
Site Investigations: Methods of explorations. Planning of Investigations, Depth of exploration, Number of boreholes, Undisturbed and Disturbed samples. Types of samplers. Brief description of procedures of sampling, Transportation and Storage of samples. Geophysical methods of investigations

 

Suggested Readings:

1.Engineering in Theory & Practice Vol. I by Alam Singh, CBS Publishers and Distributers, Delhi.
2- Geotechnical Engineering by Purushottam Raj, Tata Mc Graw Hills, Delhi.
3- Soil Mechanics in Engineering Practices by Terzaghi & Peck, John Wiley & Co.
4- Soil Mech. & Foundation Engineering by K.R. Arora, Standard Publishers and Distributers, Delhi.
5.Theory and Practice Of Foundation Design by Som and Das, PRENTICE Hall of India Delhi (PHI).
6. Soil Mechanics in Engineering and Practice by Terzaghi, CBS Publishers and Distributors.
7.Getechnical Engineering by Gulhati and Datta, Tata Mc Graw Hill, Delhi.
8. An Introduction to Geotechnical Engineering by Robert D.Holtz, William D. Kovacs, Thomas C. Sheahan, Pearson Education Delhi.