Victoria Chapter

Introducing Geotechnical Design
to Shallow Geothermal Systems

Professor Ian Johnston

Presented by Ian Johnston, Professor of Geotechnical Engineering, Department of Infrastructure Engineering, University of Melbourne

ABSTRACT

Shallow geothermal systems make use of the ground within a few tens of metres of the surface as a heat source in winter and a heat sink in summer to heat and cool buildings. A ground source heat pump or GSHP, in combination with ground loops carrying water, is used to move the heat from the ground to a building and vice-versa. The advantages of these systems are that they can reduce energy consumption and running costs by factors of about 4 or 5 and can similarly reduce greenhouse gas emissions.

This presentation will explain the principles of the technology and give examples of installations. Current design methods will be discussed. It will be argued that the understanding of the below-ground component performance is still too crude and conservative. Geotechnical engineers are now becoming involved and it is likely that their contributions will significantly benefit system efficiency, economy and effectiveness. Some recent developments on system design will be presented.

ABOUT PROFESSOR IAN JOHNSTON

Ian Johnston is originally from New Zealand but received the majority of his education in England. He obtained a Bachelors degree in civil engineering in 1968 and a PhD in geotechnical engineering in 1972. Both degrees were from the University of Southampton. After 3 years working in Europe, the USA and the Persian Gulf, he moved to Australia to join the Department of Civil Engineering at Monash University where he was a lecturer, senior lecturer and associate professor. In 1993, he was appointed Professor and Dean of Engineering at Victoria University of Technology. In February 1998, he returned to full time consulting with Coffey Geotechnics as a Senior Principal. In May 2009, he moved back to academia to take up his current appointment.

Although his interests have covered a wide range of topics, Ian is probably best known for his work on soft rock in civil and mining engineering. He has published over 100 technical papers and has undertaken substantial work in Australia and overseas both as an academic and as a consultant. Since taking up the University of Melbourne position, he has developed a strong interest in shallow geothermal energy. His research group is now growing rapidly and has established several monitored field test facilities.

Ian has received several teaching and research awards and has had considerable input into the activities of many professional societies, committees, boards and other technical groups, locally, nationally and internationally. He regularly lectures in the UK and abroad, and has acted as a specialist consultant in civil, geotechnical and offshore engineering on many projects. He is a Fellow of the Institution of Civil Engineers and of the Royal Academy of Engineering.

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