This course covers constitutive modelling of soils, including: the role of constitutive modelling in cost-efficient and sustainable geotechnical engineering; drained and undrained behaviour; stress and strain variables; elastic models (linear isotropic elasticity, drained and undrained moduli, non-linear, anisotropic); elastic-perfectly plastic models (yield surfaces for undrained behaviour (Tresca, Von Mises), yield surfaces for drained behaviour (Mohr-Coulomb, Drucker-Prager), flow rule and dilation angle); elasto-plastic models (yield surface, flow rule and hardening law, soil behaviour interpreted in terms of elastic and plastic strains); shearing and critical states; Modified Cam Clay (MCC) as an example of an elasto-plastic critical state model; soil strength and index tests interpreted though MCC; complexities of real soil behaviour and development of advanced constitutive models.

2 lectures per week

6 tutorial classes

None

None

75% Written Examination

25% Coursework Report: Students will be required to write a code to run simulations using the Modified Cam Clay (MCC) model. The code can be written in Fortran, C, Python, MATLAB or other computer languages.

The aims of this course are to:

■ provide students with an in-depth knowledge of constitutive modelling of the mechanical behaviour of soils;

■ enable students to select and use constitutive models appropriately when undertaking computational modelling or analytical calculations in geotechnical engineering;

■ enable students to appreciate the implications of different choices of constitutive model;

■ provide students with a deeper understanding of the mechanical behaviour of soils through the use of constitutive modelling;

■ proved students with understanding of the application of numerical analysis in geotechnical design, considering the sustainability, efficiency, practicality, and accuracy.

By the end of this course students will be able to:

■ describe the principle features of elastic, elastic-perfectly plastic and elasto-plastic constitutive models for soils and the assumptions or limitations of each type of model;

■ select and use different types of constitutive model appropriately for different applications in geotechnical engineering;

■ perform simulations of soil behaviour (at a stress point level) during isotropic loading/unloading and drained or undrained shearing using the Modified Cam Clay (MCC) elasto-plastic model;

■ interpret laboratory test data within the framework of critical state soil mechanics and determine the values of constitutive model parameters from laboratory test data;

■ describe some of the complexities of real soil behaviour that cannot be represented by models such as MCC (including behaviour at small strains, response to cyclic loading, anisotropy, destructuration and creep/rate dependency) and outline the principles of advanced constitutive models intended to address each of these issues;

■ apply constitutive models in optimising geotechnical design and reducing the carbon footprint of geotechnical engineering;

■ understand how constitutive models are used in geotechnical design using finite element modelling.

Students must attend the degree examination and submit at least 75% by weight of the other components of the course's summative assessment.

Students must attend the timetabled laboratory classes.

Students should attend at least 75% of the timetabled classes of the course.

Note that these are minimum requirements: good students will achieve far higher participation/submission rates.  Any student who misses an assessment or a significant number of classes because of illness or other good cause should report this by completing a MyCampus absence report.