31596 - Principles of Geotechnics T

Academic Year 2018/2019

  • Teaching Mode: Traditional lectures
  • Campus: Bologna
  • Corso: First cycle degree programme (L) in Civil Engineering (cod. 8888)

Learning outcomes

The course aims at giving students the principles and the fundamental concepts of Soil Mechanics. The students will learn about 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

Index properties of soils and classification systems. The origin and nature of soils. Soil mineralogy. Soil structure and fabric. Phase relationships. Grain size and grain size distribution. Atterberg limits. Soil classification systems.

Geostatic stresses. Mechanics and models. Basic continuum mechanics applied to soils. Vertical stress distribution due to self-weight. Lateral earth pressure at rest. Loading history. Preconsolidation stress. Overconsolidated soils. Stress distribution due to surface loads from elastic theory.

Water in soils. Pore water properties. The principle of effective stresses. Capillarity, shrinkage and swelling phenomena in soils. Flow through porous media: Darcy's law and soil permeability. Seepage forces, quicksand and liquefaction. Two dimensional flow and flownets.

Soil compressibility and consolidation rate. The oedometer test. Terzaghi's theory of one dimensional consolidation. Determination of compression and consolidation coefficients from oedometer tests. Primary compression settlement calculation. Secondary compression.

Shear strength and deformability of soils. General aspects. The Mohr-Coulomb failure criterion. Analysis in terms of effective and total stresses. Shear strength parameters and their experimental determination: direct shear and triaxial laboratory tests. Shear strength and deformability of coarse-grained and fine-grained soils. Residual shear strength. Short-term and long-term stability.

Soil investigation. Purposes of soil investigations. Soil exploration methods. Boreholes and soil sampling. In-situ testing: standard penetration test, cone penetration test, piezocone test, vane shear test. Site measurements.

Lateral earth pressure. Plasticity and limit equilibrium methods. Active and passive earth pressure, coefficients of earth pressure, active and passive pressure distributions. Critical height of unsupported cuts in cohesive soils.

Readings/Bibliography

Lecture notes.

Riccardo BERARDI: Fondamenti di Geotecnica. Città Studi Edizioni, Third Edition, 2017.

Laura TONNI e Guido GOTTARDI: Esercizi di Geotecnica. Esculapio Bologna, 2010.

Teaching methods

They include both lectures and tutorial exercises, in which theory is applied to solve simple common geotechnical problems. A visit to the Soil Mechanics Laboratory is typically arranged.

Assessment methods

Assessment includes both written and oral exam.

Office hours

See the website of Guido Gottardi