Spotlight on a student: Yu Zhong

Improving our understanding of energy retaining walls by field investigation and numerical modelling

Yu (Cherry) Zhong is a PhD candidate in the Department of Infrastructure Engineering in the Faculty of Engineering and IT. Her research focuses on energy retaining walls, an innovative and economic form of Ground Source Heat Pump systems.

We interviewed Cherry about her research and future plans after she completes her PhD in mid 2022.

What is your research about?

My research focuses on energy retaining walls, an innovative and economic form of Ground Source Heat Pump (GSHP) systems. GSHP systems utilise the ground as a heat source and heat sink, which provide a viable solution for building thermal comfort and industrial heat processing.

Energy retaining walls incorporate geothermal pipes with circulating water, allowing the wall to act as ground heat exchangers (GHEs) in addition to providing structural stability. This approach eliminates the necessity for drilling purpose built GHEs, substantially reducing the required capital investment and furthering the economic viability of GSHP systems.

As there are insufficient studies on energy retaining walls around the world and limited field experiences, my research involves extensive field investigation in combination with numerical modelling. A pilot energy wall located in Melbourne, Australia, believed to be one of the first few fully instrumented energy soldier piled walls in the world, is used as a case study in this research. This work was undertaken in collaboration with the Melbourne Metro Rail Authority, the Early Works team, and Cross Yarra Partnership. The field data not only allows us to understand the thermal and thermo-mechanical performance of the wall in real practice, but also provides  important datasets for the validation of analytical or numerical approaches.

Due to the complex nature of energy retaining walls, numerical models built in COMSOL Multiphysics are broadly employed to assess the system’s performance under various environmental and design conditions.

Overall, my research outcomes provide more confidence in the analysis and design of energy retaining walls. This will allow these systems to be more easily adopted, promoting the wider utilisation of GSHP systems.

Image: Yu Zhong onsite as part of the Metro Tunnel Project in Melbourne.

Why did you choose this research topic?

I started my research journey in 2018 as a research assistant in the Porous Media Research Laboratory (PMRL) group, working at one of the new Melbourne Metro stations. The concept of GSHP systems and energy geo-structures really fascinated me. It provided huge value to our research community, as well as in real-world applications. Working with a combination of clean, renewable geothermal energy and geotechnical structures aligns with my interests and career goals; which is to make infrastructures serve the world in better and more sustainable ways. I’m also fortunate to have the chance to be exposed to multiple aspects of research, including field investigations, laboratory work, and numerical modelling.

Who are your supervisors?

My primary and co-supervisors are Professor Guillermo Narsilio and A/Professor Mahdi Disfani from the University of Melbourne, and Dr. Nikolas Makasis from Cambridge University in the UK.

What do you want to do next?

After completing my PhD, I plan to devote my career to building a sustainable future. I am driven by my frustration in the slow uptake of renewables, the inadequate support for renewable infrastructures, and the insufficient development of policy and enforcement. I am eager to play my part in the clean energy transition.

Have you received any awards?

I have received a Melbourne Research Scholarship, which helped to supported my PhD. I was also a finalist for the Golder Associates Award, and runner up for the Australian Geomechanics Society’s Jack Morgan Young Geotechnical Practitioners Award in 2021. I also received the PMRL’s Author of the Year Award in 2020 for my publications.

Further information

Cherry and her supervisors are happy to receive questions about her research, and can contacted via email at and

More Information

Melbourne Energy Institute

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