Investigating the behaviour of crushable soils using the discrete element modelling

Improve our understanding of crushable soils 

About the project

If you are keen to advance your career in geotechnical engineering and concerned about improving civil infrastructure, the University of South Australia – Australia’s University of Enterprise – is offering a hands-on project-based PhD within the Sustainable Infrastructure and Resource Management (SIRM) research concentration, in partnership with Rio Tinto. 

The failures of various civil infrastructures, including slopes, earthen dams, roads, etc., often involve the reduction of shear strength in soils. Excessive loads can lead to the crushing of individual particles in soils and this phenomenon alters the microstructure of soil, ultimately diminishing its shear strength.  
Understanding the behaviour of crushable soils holds significant importance in numerous civil engineering applications. However, effectively capturing the mechanism of particle crushing poses challenges in laboratory and field studies, impeding progress in understanding the effects of particle breakage. 

To address these challenges, our project will use the numerical discrete element method (DEM) to generate crushable soils, analyse their microstructure, and observe their failure mechanisms under excessive loading conditions.  

We aim to develop a novel framework to assess the failure of crushable materials within the context of fundamental critical state soil mechanics and provide a deeper understanding of the influence of particle breakage on the mechanical behaviour of soils. Our research can potentially contribute to the development of constitutive models for such materials, benefiting the broader engineering community. 

You will join the SIRM research concentration, working under the supervision of esteemed researchers in the geotechnical community. They maintain strong links with over 35 local, national, and international organisations, fostering a dynamic network that we would encourage you to access and develop. This collegial group is committed to supporting PhD students in geotechnical engineering and related fields, providing mentorship, guidance, and resources, helping you to prepare for your future career.  

You will have full access to the geotechnical engineering laboratory which is equipped with four cutting-edge triaxial test setups, two of which possess small strain stiffness measurement capabilities, one with unsaturated testing capabilities, and another with cyclic load testing capabilities. DSS (Direct Simple Shear) testing equipment is also available for experimentation. 

What you’ll do

In this project-based research degree, you will learn the DEM code for crushable soils and replicate the laboratory or field condition in the DEM simulations. You will also be mentored in performing a series of laboratory triaxial test, simple shear test and other associated tests to validate the results from DEM. Advanced microstructure analysis in micro-CT scan will help you to develop a deeper understanding of the nature of crushable soils. 

We will support you to submit to reputable journals, such as Geotechnique, Journal of Geotechnical and Geoenvironmental Engineering. You will also have the opportunity to attend conferences, such as GeoCongress and The International Society for Soil Mechanics and Geotechnical Engineering, to garner feedback on your research and start building your professional networks. 

Where you’ll be based

You will be based in the Sustainable Infrastructure and Resource Management (SIRM) research concentration. Our future depends on the increased application of sustainable infrastructure and responsible use of our natural resources. SIRM facilitates this goal by conducting research in three main streams: Natural Resources and Environmental Resilience, Innovative Infrastructure and Asset Management, and Smart Communities. 

The construction industry is an essential part of our lives, but it is one of the highest contributors to climate emissions.  SIRM is committed to meaningful research that can help re-shape this industry into a leader in sustainable practices.  SIRM also works directly with the resource sector, particularly water and forestry, to inspire innovative management.  

SIRM brings together diverse research expertise to address significant challenges for industries and the society at the interface of the natural and the built environments at both the macro and micro level. Financial Support

This project is funded for reasonable research expenses. Additionally, a living allowance scholarship of $32,500 per annum is available to Australian and New Zealand citizens, permanent residents of Australia. Australian Aboriginal and/or Torres Strait Islander applicants will be eligible to receive an increased stipend rate of $46,653 per annum (2023 rates). A fee-offset or waiver for the standard term of the program is also included for this group.  For full terms and benefits of the scholarship please refer to our scholarship information. International applicants will not be eligible to receive the scholarship.

Eligibility and Selection 

This project is open to application from both domestic and international applicants.

Applicants must meet the eligibility criteria for entrance into a PhD. All applications that meet the eligibility and selection criteria will be considered for this project. A merit selection process will be used to determine the successful candidate.

The successful applicant is expected to study full-time and to be based at our Mawson Lakes Campus in the north of Adelaide. Note that international students on a student visa will need to study full-time.

Essential Dates 

Applicants are expected to start in a timely fashion upon receipt of an offer.  Extended deferral periods are not available. Applications close on Friday, 29th September.