Critical State Soil Mechanics

Recommended Prerequisites

Soil Mechanics I and II, Foundations

Teaching Methods

Theoretical lectures with a detailed exposition of the main concepts, principles and theories using overhead projection and the resolution of exercises that exemplifies the application of the theoretical subjects. Tutorial lectures where the students solve practical applications under the supervision of the lecturer. Laboratory lectures for the execution of experimental work to obtain the soil parameters or just calculate the data of the tests results exposed or follow the execution in the laboratory.

Learning Outcomes

The aim is to explore, in some detail, the mechanical properties of soils and to develop appropriate mathematical models to describe and predict the engineering behaviour of the ground.  By the end of the course you will be familiar with modern approaches to determining the strength and stiffness of soils and the application of these properties in practice.

Work Placement(s)

No

Syllabus

The concept of effective stress.

Concepts of stress and strain. Elastic, linear, rigid and perfect plastic models.

Stress paths and earth pressure at rest.

Shear strength and failure criteria.

Drained strength of sands and clays, peak, post-rupture and residual strength, the Critical State Concept, the work of Hvorslev.

Ideal porous elastic materials.

Compressibility of natural clays.

Odometer test.

The Critical State framework and the work of Rendulic.

Elastic-plastic volume change of clays.

Undrained strength.

Cone penetrometer, vane and triaxial test.

The stress-strain behaviour of clays.

Elasticity theory versus plasticity theory.

Yield locus, flow rule, strain hardening law.

Isotropic models and anisotropic models.

Cam Clay and modified Cam-Clay models.

Melanie and MIT models.

Head Lecturer(s)

Luís Joaquim Leal Lemos

Assessment Methods

Evaluation
The evaluation consists mainly on a final exam, participation, reports with the resolution of practical applications, written and oral presentation and discussion of practical works and laboratory tests.: 100.0%

Bibliography

• C.R. Scott - An Introduction to Soil Mechanics and Foundations, Applied Science Publishers.

• Craig - Soil Mechanics, Spon Press.

• Atkinson - An Introduction to the Mechanics of Soils and Foundations, McGraw-Hill.

• David Muir Wood - Soil behaviour and critical state soil mechanic, Cambridge.