The last decade has seen an increased use of Artificial Ground Freezing (AGF) to successfully complete underground structures under very diverse geotechnical conditions all over the world. The growing awareness of the merits of AGF as a temporary ground improvement system with minimal environmental impact is directly related to the progress made in the understanding of the behaviour of frozen soils.
Owing to the strong non-linearity of the governing equations, and their reciprocal coupling, the analysis of the Thermo-Hydro-Mechanical (THM) coupled behaviour of frozen soils requires the adoption of numerical techniques. Constitutive models for the behaviour of frozen ground have been developed and implemented with various degrees of sophistication, depending on their particular application purposes. However, a solid framework including also transient effects has yet to be established for fully coupled THM approaches and there is still scope for fundamental research to be carried out on experimental characterisation and constitutive modelling of frozen/unfrozen ground.
The proposed PhD project will investigate experimentally the behaviour of soil on freezing/thawing cycles and then calibrate and improve an existing fully-coupled THM constitutive model against the experimental results. The project will provide valuable insight into the mechanical behaviour of frozen/unfrozen soils, drawing upon multi-disciplinary knowledge at the interface between soil mechanics, thermodynamics, soil physics, material science, geology and industry.
The final goal of the research is to model AGF as a construction process accurately, thus gaining confidence in the engineering design of this type of works. However, applications of potential findings span a number of sectors in engineering from the analyses of frost heave to the effect of freezing-thawing cycles in cold regions, to the identification of potential hazards to infrastructure connected to permafrost degradation due to global climate change.
Applicants should have (or expect to obtain by the start date) a high 2:1, preferably a 1st class honours degree in an Engineering or related subject. Knowledge of continuum mechanics, thermodynamics, soil mechanics, and geotechnical engineering is desirable (any experience in equipment development and /or constitutive modelling would be an advantage).
EPSRC DTP studentships are fully-funded (fees and maintenance) for UK students or provide fees only for EU students from outside the UK. Further details about eligibility can be found at: https://epsrc.ukri.org/skills/students/help/eligibility/.
To apply for this studentship, please send a CV, a transcript and a cover letter to email@example.com, with subject "Artificial Ground Freezing - PhD", to arrive no later than midnight on 31 January 2019. Queries about the post should also be addressed to Prof. Giulia Viggiani at firstname.lastname@example.org.
Please note that any offer of funding will be conditional on securing a place as a PhD student. Candidates will need to apply separately for admission through the University's Graduate Admissions application portal; this can be done before or after applying for this funding opportunity. Note that there is a £60 fee for PhD applications. The applicant portal can be accessed via: www.graduate.study.cam.ac.uk/courses/directory/egegpdpeg. The final deadline for PhD applications is 30 June 2019, although it is advisable to apply earlier than this.
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