99640 - Principles of Geotechnics

Learning outcomes

The course aims at giving students the principles and the fundamental concepts of Soil Mechanics. At the end of the class, the students understand the behaviour of soils as engineering materials and the main experimental methodologies for the determination of their physical and mechanical parameters. The final goal is to provide a sound basic knowledge for solving simple geotechnical problems as well as for carrying out the subsequent work on Geotechnical Engineering.

Course contents

An introduction to Soil mechanics

Part I - Development of a mechanical model for soil

1 Basic characteristics of soils

1.1 The origin of soils

1.2 The nature of soils

1.3 Plasticity of fine-grained soils

1.4 Particle size analysis

1.5 Soil description and classification

1.6 Phase relationships

1.7 Problems

2 Seepage

2.1 Soil water

2.2 Permeability and testing

2.3 Seepage theory

2.4 Flow nets

2.5 Problems

3 Effective stress

3.1 Introduction

3.2 The Principle of Effective Stress

3.3 Response of effective stress to a change in total stress

3.4 Influence of seepage on effective stress

3.5 Liquefaction (Brief overview)

3.6 Problems

4 Consolidation

4.1 Introduction

4.2 The oedometer test

4.3 Estimating compression and swelling parameters from index tests

4.4 Consolidation settlement

4.5 Degree of consolidation

4.6 Terzaghi’s Theory of One-Dimensional Consolidation

4.7 Determination of coefficient of consolidation

4.8 Secondary compression

4.9 Problems

5 Soil behaviour in shear

5.1 An introduction to continuum mechanics

5.2 Simple models of soil elasticity (Brief overview)

5.3 Simple models of soil plasticity (Brief overview)

5.4 Laboratory shear tests – the direct shear test

5.5 Laboratory shear tests – the triaxial test

5.6 Shear strength of coarse-grained soils

5.7 Shear strength of saturated fine-grained soils

5.8 The Critical State framework (Brief overview)

5.9 Residual strength (Brief overview)

5.10 Problems

6 Ground investigation and Monitoring

6.1 Introduction

6.2 Methods of intrusive investigation

6.3 Sampling

6.4 Selection of laboratory test method(s) (Brief overview)

6.5 Borehole logs

6.6 Cone Penetration Testing (CPT)

6.7 Flat dilatometer test (DMT) (Brief overview)

6.8 Geophysical methods (Brief overview)

6.9 Field instrumentation for evaluating geotechnical performance (Monitoring)

6.10 The observational method

7 In-situ testing

7.1 Introduction

7.2 Standard Penetration Test (SPT)

7.3 Cone Penetration Test (CPT)

7.4 Flat dilatometer test (DMT) (Brief overview)

7.5 Selection of in-situ test method(s)

Part II Applications in geotechnical engineering

8 Limiting earth pressures

8.1 Introduction

8.2 Limiting earth pressures from Rankine’s Theory

8.3 Earth pressure at rest and mobilisation of limit pressures

8.4 Coulomb’s Theory of Earth Pressure (Brief overview)

8.5 Problems

9 Retaining structures (Brief overview)

9.1 Introduction

9.1 Gravity retaining structures (Brief overview)

Readings/Bibliography

Knappett, J., Craig, R. (2019-10-11). Craig's Soil Mechanics, 9th Edition

Teaching methods

The course is divided in two modules.

The first module is taught by Professor Michela Marchi.

The second module is taught by Professor Ilaria Bertolini.

Assessment methods

Assessment is based on a final exam, aimed at assessing the understanding of concepts and the acquisition of related competences. The exam consists of a preliminary written test, which requires the solution of numerical exercises, and a final oral session, which deals with more theoretical issues. The exam, in both written and oral parts, concern all the topics developed during the lessons.

Higher grades will be awarded to students who can demonstrate an organic understanding of the subject, a capacity of presenting the course contents in a clear and concise way and an ability of critically discussing the results achieved. To obtain a passing grade, students are required to show their knowledge of at least the key concepts of the subject, some ability for their critical application and a correct use of technical language. A failing grade will be awarded if the student shows knowledge gaps in key-concepts of the subject, inappropriate use of language, and/or logic failures in the analysis of the subject.

Teaching tools

Blackboard and slides

Office hours

See the website of Michela Marchi

See the website of Ilaria Bertolini