Module Catalogue 2024/25

Pre Requisite Comment

For part time, CEG8201 Geomechanics should be studied prior to this module. For students following other programmes an equivalent background in civil engineering, soil mechanics and foundation design is required.

Co Requisite Comment

None

Aims

The aims of this module are:

1. To introduce a range of constitutive models capable of describing soil behaviour.
2. To provide an understanding of the principles of numerical modelling.
3. To enable students to develop a working knowledge of a geotechnical finite element program.
4. To introduce students to the benefits of automating numerical analysis through scripting.

Module Summary:

This module will deliver an introduction to the basic features of commonly used constitutive models capable of describing saturated and unsaturated soil behaviour and will provide an understanding of the principles of numerical modelling. It will introduce the advantages and limitations of different models of soil behaviour, and strategies to select the appropriate soil parameters. Presentations and specially prepared notes and tutorial exercises are combined with the use of geotechnical finite element software to provide the students with a thorough knowledge and understanding of soil modelling. The use of automation to make finite element analysis an even more powerful design tool will be introduced using a Python-based remote scripting interface.

Outline Of Syllabus

1. Introduction – design objectives, theoretical considerations, physical and analytical models.
2. Elastic models – characteristics of soil behaviour, strain increments and stress variables, elasticity, drained triaxial test, undrained triaxial test, measurement of elastic parameters, oedometer, in-situ geophysics, plate loading, pressuremeter, anisotropy, nonlinearity-secant and tangent stiffness, advantages and limitations of elastic models.
3. Elastic-plastic models – yield surface-Tresca criterion, Von-Mises criterion, Mohr-Coulomb criterion, hardening models, plastic flow rules.
4. Elastic-perfectly plastic Mohr-Coulomb model – Elastic properties, yield criterion, flow rule, elastic- plastic stiffness matrix, selection of soil parameters, extended Mohr-Coulomb model
5. Cam-clay model –3D space, Isotropic consolidation, critical state line, model ingredients, drained test on NC clay, undrained test on NC clay, elastic properties, yield surface, flow rule, hardening rule, compliance matrix.
6. Stress paths – foundation loading, slope stability, stress path, 2D stress space, 3D stress space, examples of stress paths, pore pressure changes, application of stress paths.
7. Finite element method – Introduction; how does the FE work, mathematical foundations, nodes, elements and shape functions, principle of virtual displacement, external work, internal work.
8. Automation – command line in Plaxis 2D, Python remote scripting interface, basic programming in Python, automation of input (model building and construction sequencing), and automation of output (results post-processing).

Intended Knowledge Outcomes

The mapping of certain AHEPv4 learning outcomes to each intended knowledge outcome is indicated in each point. On successful completion of this module, students will have:

The ability to describe the basic features of commonly used models of soil behaviour (M1, M2).

The ability to understand the advantages and limitations of different models of soil behaviour and to select the appropriate soil parameters (M2, M3).

The ability to use a finite element program to analyse a wide range of geotechnical problems such as offshore foundation or embankment loading situations (M3, M4).

The ability to understand the benefits of automating numerical analysis and to use scripting to automate basic tasks in a geotechnical finite element program (M3).

Intended Skill Outcomes

The mapping of certain AHEPv4 learning outcomes to each intended skill outcome is indicated in each point. The module should enable the student to become proficient in:

Study skills - research, time management and information processing (C16, M2, M3)
Problem solving skills - application of appropriate soil models for the analysis and design of geotechnical structures (M3, M5, M13)
Communication skills - verbal (inquiry and explanation), written (geotechnical analysis and documentation), visual/graphical (diagrams and finite element/discrete element input/output) (M17)
Evaluation skills – manual (M4)
Workplace skills - group and team working (C16, M11)

Teaching Rationale And Relationship

The module is taught as an intensive block in order to provide an immersive learning experience with a flexible integration of lecture, tutorial and practical sessions. This format also allows part time and full time students and CPD delegates to attend. Teaching and learning is by a combination of presentations, directed reading and through the use of specially prepared notes to explain the principles of numerical modelling in geotechnical engineering, small group teaching exercises, guided tutorials on geotechnical finite element and discrete element software. The computer practical sessions provide real-world examples of the theory presented in the lectures. It allows opportunities to develop numerical analysis skills and it relates directly to the assessment.

Assessment Rationale And Relationship

A formal examination will be used to assess understanding of theoretical aspects of commonly used models of soil behaviour and stress paths.

The coursework will develop students' understanding of the constitutive and numerical aspects of geotechnical design of earth structures and enhance their technical skills in undertaking parametric studies to further evaluate modelling outputs.

General Notes

N/A