- Title
- Advanced numerical methods for predicting the behaviour of soft clay soils
- Creator
- Lester, Alexander Michael
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2020
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- Soft clay soils can form under many different geological conditions, and are encountered on a great number of civil engineering projects worldwide. When structures such as road embankments are founded on soft clays, they will exhibit time dependent deformations. Settlements can be in the order of metres and can continue to accumulate for years after the commencement of construction. The complex behaviour of soft clays means that accurate prediction of these settlements can be very challenging, and inaccurate predictions can often lead to significant costs in remedial work. In this thesis, a series of numerical methods is developed and then applied in predicting the response of soft clays to external loads. The methods include some improvements to a yield surface for estimating the onset of plastic deformation, the 3D generalisation of a constitutive model for soft clays and a new method of modelling prefabricated vertical drains (PVDs), which are often used to accelerate consolidation settlements. Application of the numerical methods involved the development of a geotechnical model for a test site in Ballina (NSW), Australia, where trial embankments have been constructed over soft clay. Following calibration of material parameters on laboratory test results, finite element simulations of the trial embankment over soft clay improved with PVDs were carried out. Simulated and measured settlements and pore pressures correlated very well, even without performing any back analysis to refine the predictions. There are a number of ways in which the numerical methods could be improved in extending their application to practical problems. However, their presentation in this thesis has made for a very good starting point and a substantial contribution in working towards the accurate prediction of soft clay settlements under externally applied loads.
- Subject
- soft clays; prefabricated vertical drains; finite element method
- Identifier
- http://hdl.handle.net/1959.13/1415505
- Identifier
- uon:36915
- Rights
- Copyright 2020 Alexander Michael Lester
- Language
- eng
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Thesis | 5 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 405 KB | Adobe Acrobat PDF | View Details Download |