Undergraduate Course: Soil Mechanics 2 (CIVE08019)
|School||School of Engineering
||College||College of Science and Engineering
|Credit level (Normal year taken)||SCQF Level 8 (Year 2 Undergraduate)
||Availability||Available to all students
|Summary||This course introduces the basic concepts of the mechanics of soils. It covers the fundamental multi-phase nature of soils, provides an understanding of soil description and classification, the effective stress concept and elementary seepage and compaction problems.
L1 Introduction to soil mechanics
Aims and challenges of geotechnical engineering. Structure of the course. Course content. References with comments. Engineering units and dimensions. Introduction to laboratory programme.
L2 Mass-volume relationships 1
Multiphase nature of soils. Volume relationships: void ratio, porosity, degree of saturation. Mass relationships: water content, bulk density, solid density, dry density, unit weight, submerged unit weight, specific gravity, relative density.
L3 Mass-volume relationships 2
Soil phase diagram. Worked example.
L4 Mass-volume relationships 3
L5 Nature and formation of soils
Definition of a soil. Physical and chemical weathering. Residual and transported soils. Clay soil.
L6 Description and Classification of soils
Soil description and classification (BS593 ). Material and mass characteristics of a soil. Particle size analysis, grading curves, effective grain size and uniformity coefficient. Limit tests (BS1377). Plasticity chart. Engineering applications of the Atterberg limits.
L7 Effective stress concept 1
Principle of effective stress. Physical interpretation. Total and effective vertical stress and pore water pressure.
L8 Effective stress concept 2
Total and effective stresses. Worked example.
L9 Effective stress concept 3
Partially saturated soils. Capillary head. Worked example.
L10 Stresses in soils 1
Geostatic stress condition. Lateral stress coefficient. Horizontal and vertical stresses. Normal and overconsolidation. Ko condition.
L11 Stresses in soils 2
Definition of stresses in two dimensions. Mohr's diagram method of stress analysis. Total and effective stress Mohr's circles. Worked example.
L12 Stresses in soils 3
Further worked examples.
L13 Permeability of soils 1
Flow of water through soil: total head, pressure head. Darcy's law: hydraulic gradient, permeability coefficient k, typical values of k, Hazen's equation. Laboratory measurement of permeability: constant head permeameter and falling head permeameter.
L14 Permeability of soils 2
Reliability of laboratory measurement of permeability. Field methods of measurement: well pumping test.
L15 Seepage in soils 1
One-dimensional seepage: effective stress under seepage, critical hydraulic gradient, quick sand phenomenon, piping failure. Two-dimensional seepage: steady state flow and transient flow, assumptions and derivation of differential equation for 2-D seepage.
L16 Seepage in soils 2 and concluding remarks
Flow net construction and uses in the solution of geotechnical seepage problems. Worked example. Recap on the main aspects of the topics covered in this course.
L17 Theory of compaction
Definition of compaction. Soil properties and definitions: air voids, dry density, phase relationships.
L18 Laboratory compaction tests
Light compaction, heavy compaction, vibratory compaction. Field density determination: sand replacement, core cutter. Optimum moisture content and maximum dry density.
L19 Field compaction plant
Smooth wheeled rollers, pneumatic-tyred rollers, vibratory compactors, sheepsfoot rollers.
Tutorial exercises are given with supervised tutorial classes. The aim is to give the students ample opportunities to develop skills in applying the theories and methods learned to solve elementary geotechnical engineering problems. The exercises cover a great variety of elementary geotechnical problems in varying degrees of difficulty.
Tutorial Exercise 1 Mass-volume relationship and soil classification:
This tutorial is intended for developing skills in basic calculations of the masses and volumes of the different components of a soil. Exercises for soil description and soil classification are also included.
Tutorial Exercise 2 Total and effective stresses:
This tutorial is intended for students to develop skills in calculating the pore water pressure, total and effective geostatic stresses given the soil profile. Exercises for using Mohr's circle method of stress analysis are also included.
Tutorial Exercise 3 Permeability and Seepage:
This tutorial is intended for developing skills in solving geotechnical problems relating to soil permeability and seepage. The student should become familiar with the deduction of coefficient of permeability from different laboratory and in-situ methods, and the solution of 1-D and 2-D seepage problems.
Tutorial Exercise 4 Compaction:
Phase relationships; compaction curves; air void contours.
Laboratory classes are undertaken in the Soil Mechanics Laboratories. The students work in groups under the supervision of a laboratory demonstrator. The aim is to train the student in proper laboratory test techniques, including the analysis of results and the evaluation of relevant properties.
Laboratory 1 Determination of plastic and liquid limits:
The experiments to determine the plastic limit and liquid limit of a clay soil are performed in accordance to BS1377: 1990 . The results lead to the determination of the plasticity index and the use of the plasticity chart.
Laboratory 2 Compaction, maximum dry density:
The experiment to determine the relationship between dry density and water content is performed in accordance to Test 12 of BS1377: 1990. The optimum water content which gives the maximum dry density for a certain compactive effort is determined.
Laboratory 3 Determination of coefficient of permeability:
The coefficient of permeability of a sand is determined by using a constant head permeameter.
Laboratory 4 Direct shear box test:
The shear strength parameters of a dry sand are measured by using a direct shear box. The stress and displacement changes during shearing are also studied. This experiment forms the first introduction into shear strength of soils, which is covered extensively in Geotechnical Engineering 3.
Entry Requirements (not applicable to Visiting Students)
|| Students MUST have passed:
Civil Engineering 1 (CIVE08001)
||Other requirements|| None
Information for Visiting Students
|High Demand Course?
Course Delivery Information
|Not being delivered|
On completion of this course, the student will be able to:
- Demonstrate ability to explain the multiphase nature of soils and to derive quantities relating to the volumes and masses of the different phases of a soil
- demonstrate ability to apply the effective stress concept to solve elementary geotechnical problems
- describe and classify a soil according to BS5930
- demonstrate skills in soil permeability and compaction measurement and skills in the solution of seepage related problems
J.A. Knappett and R.F. Craig, Craig's Soil Mechanics, Spon Press, 2012.
T.W. Lambe and R.V. Whitman, Soil Mechanics, Wiley, SI version, 1979.
G.E. Barnes, Soil Mechanics: Principles and Practice, Macmillan, 2010.
M. Bolton, A Guide to Soil Mechanics, M.D.& K.Bolton, 1991.
W. Powrie, Soil Mechanics: Concepts and Applications, CRC Press, 2013.
|Graduate Attributes and Skills
|Keywords||soil mechanics,multi-phase,soil description,stresses,Mohr's circle
|Course organiser||Dr Jin Sun
Tel: (0131 6)51 9028
|Course secretary||Mr Craig Hovell
Tel: (0131 6)51 7080