Assignment 2 – Finite Element Modelling

ECMM109 - Advanced Geotechnical Engineering

Feb 2022

The goal of this assignment is to develop a model able to predict stress, strain, and settlements of a soil layer on
which a foundation is going to be laid.

A 3.0 m wide, 0.5m deep strip (continuous) foundation is to be constructed on a 10 m layer of soil. The foundation
carries a uniform pressure of 130 kPa. The geometry of the problem is shown in Figure 1. Using both the Mohr-
Coulomb and the modified Cam clay models for the foundation soil and the soil parameters obtained in Assignment
1, carry out a finite element analysis and compute:
a. The settlement of the foundation under the applied load;
b. The distribution of stresses and strains in the soil;
c. Any additional analysis that you may see appropriate.
d. Discuss the results.

Due to the symmetry, only half of the domain can be modelled.

Assuming that the triaxial test results that you analysed in Assignment 1 were obtained on undisturbed samples of
soil taken from this site, use the soil parameters you have determined in Assignment 1 to complete Table 1 and the
FE analysis.
NOTE: You may assume reasonable values for some of the parameters if you have not determined them in
Assignment 1.


Figure 1. Geometry of the problem


Table 1. Soil parameters
κ λ  M 'p  k N φ’ c’


κ = slope of the unloading-reloading line;
λ = slope of the isotropic normal compression line;
 = Poisson’s ratio;
M = critical state parameter (gradient of the critical state line in the q:p’ space);
'p = parameter controlling the size of the yield curve (isotropic pre-consolidation pressure);
 = unit weight;
1.5 m
k = permeability;
N = intercept of the isotropic normal compression line at p’=1;
φ’ = friction angle of the soil in effective stress conditions;
c’ = cohesion of the soil in effective stress conditions.

Final submission should be in the form of a written report, word or pdf, outlining your solutions and discussion of
the results, and your Abaqus input file(s).

For the Abaqus files, please upload your CAE and INP files (named as your student number.cae and your
student number.inp) on your OneDrive and share them with me by adding the download link to the end of
your written report.

The reports should be submitted via Bart system by 28th March 2022.


Raffaele Vinai
Feb 2022