ENG 464 Assignment 1 1
ENG464 Geotechnical Engineering
Numerical analysis of consolidation
A 10 m thick clay stratum is drained on its upper surface but is effectively impervious at its lower
oundary. It is subjected to an initially uniform pore water pressure distribution of 100 kPa through
its depth. The coefficient of consolidation of this clay is approximately 0.15 m2/month; using
Taylor’s series approximation, and Gibson and Lamb’s method, using a finite difference, numerical
analysis approach, estimate the degree of consolidation of the clay at six months, and then at one
year, after the start of consolidation.
Formulae: )2( ,,1,1,1, jijijijiji uuuuu −++= +−+ β
)22( ,,1,1, jijijiji uuuu −+= −+ β
All software, spreadsheets, and other calculations used in the solution to the aforementioned
problem are to be submitted for checking.
i) Analyse the effect of the selection of value of operator β, based upon one of your solutions
to Part 1 (t = 6 months or t =1 year). State the mathematical condition required for minimum
or: then demonstrate that this is applicable in one of the cases analysed in
ii) Describe how the results of the analyses undertaken for Part 1 may influence site
management decisions for a civil engineering contractor.
(Total marks 25)
The small print
This is not a task which can be completed simply by looking at the InterNet. Original thinking is
equired, demonstrating sound reasoning and rational argument (including diagrams, calculations,
and spreadsheets developed as appropriate) to support your conclusions.
Students’ attention is drawn to the University’s policy on plagiarism.
The report must be set out as a formal technical submission/calculation sheet.
This report is worth 15 % of the marks for this unit.
Submissions are due by 1630 (ACST) on the Thursday of Week 4 (see Learnline for details).