Australia’s net-zero commitment by 2050 is accelerating offshore wind developments, many of which are underlain by clay-dominated seabeds. Past projects have encountered over-penetration during pile driving due to the initial low shaft resistance mobilised, requiring the use of hold-back anchors. 90% of a displacement pile’s axial capacity is derived from friction along the pile shaft, yet, prediction of shaft friction remains a challenge, with the industry relying on a small set of empirical based approaches that are costly to replicate. This project aims to extend lateral stress measurements in clays, to assist the interpretation of shaft friction and to ultimately determine whether field trends can be reproduced at a cost orders magnitude lower than full-scale programs.

This study used a closed-ended square instrumented pile with six total lateral stress sensors, installed in three lightly over-consolidated reconstituted soft clay deposits. Monotonic and jacked installation procedures were employed, with tension load tests performed one hour and one day after installation. Lateral stresses were recorded continuously during installation, equalisation and tension load testing. Results show that measurements from the small-scale instrumented pile are broadly consistent with field observations. Despite all clay samples prepared to the same OCR, installation lateral stresses differed by 50%. A 16% increase in normalised distance above pile tip produced approximately 50% reduction in installation lateral stress, consistent with previous field observations. Following installation, these stresses reduce to between 10 – 50%, with the relative reduction increasing with soil sensitivity. The ratio of equalised lateral stress to cone resistance varies by up to one order of magnitude, indicating cone resistance only correlations are insufficient for predicting shaft friction. Shaft friction inferred from measured stress data were broadly consistent with shaft friction deduced from actuator uplift loads, implying minimal under-registration of stresses due to cell action. Projects aiming to replace the design of displacement piles from an empirical approach to a predictive numerical framework would benefit from this research.

Tara is in her final semester of a Master of Civil Engineering. Over the past couple of years, she has worked part-time on METRONET’s Byford Rail Extension Project—her first experience on a construction site of that scale. She has been fortunate to work across the Stations, Viaduct, and Landscaping teams, learning extensively along the way. Tara has always been interested in geomechanics but had limited exposure to it on site. When it came time to choose her research project, she eagerly chose a geomechanics topic, recognising it as an excellent learning opportunity.

This study investigates how varying calcium-to-magnesium (Ca/Mg) molar ratios influence the effectiveness of microbial-induced carbonate precipitation (MICP) in improving soil stability under wave-induced erosion. The research aims to assess whether introducing magnesium ions into the cementation solution can enhance carbonate morphology, precipitation efficiency, and overall erosion resistance of treated sand. Laboratory testing was conducted in a Armfield tilting flume channel, where MICP-treated soil samples were exposed to scaled down coastal wave conditions. Multiple treatment solutions with different Ca/Mg ratios were applied to identify the optimal balance between calcite and high-magnesium carbonate formation. Key parameters, including erosion depth, mass loss and calcium carbonate content were measured to quantify performance. Scanning Electron Microscopy (SEM) analysis was also conducted to observe crystal structure and bonding characteristics. Initial findings suggest that fine tuning the Ca/Mg molar ratio and number of treatment cycles could play a significant role in optimising MICP treatment for coastal protection applications. Overall, this research hopes to contribute to the development of more durable, sustainable, and environmentally friendly solutions for mitigating coastal erosion which a growing issue affecting Perth’s coastal environments and broader shorelines across Western Australia.

Ronin O’Connor is currently completing a Bachelor of Engineering (Honours) in Civil and Construction Engineering at Curtin University. For the past two years, he has worked at Cossill & Webley – Consulting Engineers, gaining valuable experience as an Engineering Assistant on several of Perth’s largest residential and industrial land development projects. Prior to his engineering studies, Ronin played professionally in the Australian Football League (AFL) for the Adelaide Football Club between 2020 and 2021, where he competed in three senior games at the highest level. He currently continues to play semi-professionally in the WAFL competition with the Claremont Football Club alongside his work and studies.

The Project involves incorporating a 3D Hoek-Brown Criterion (extended from the 3D Jiang Mohr-Coulomb Criterion) into Bishop’s Simplified method by trigonometrically deriving the instantaneous Mohr Coulomb Parameters in terms of the 3D Hoek-Brown Criterion. The instantaneous parameters for each unit slice of a chosen open-pit slope can then be solved iteratively through the development of an VBA excel macro code. The minimum FS along the defined circular slip surface is then computed using the excel solver function and the equations from Bishop’s Simplified Method. The results produce a consistently higher factor of safety with lower variance, thus indicating a potential for more vigorous slope designs to be achieved if utilised.

Jordan is a final-year master’s student in mining engineering with one year of experience as an undergraduate project engineer, where he contributed to real-world projects in mining and LNG hydraulics. During this time, he completed a 26-week mechanical engineering internship program through the Australian Defence Force, which involved naval shipbuilding. Jordan is passionate about solving complex problems and applying analytical thinking to achieve excellence and continuous improvement in engineering operations. He is furthering his mining engineering career by transitioning into a new role at South32, where he aims to continue growing, contributing meaningfully, and working alongside forward-thinking professionals to make a lasting impact in the mining industry.

Rammed earth has recently been investigated and trialled for stabilisation using new bio-cementation techniques such as enzyme induced calcium carbonate precipitation (EICP) and microbially induced calcium carbonate precipitation (MICP), as an environmentally friendly alternative to cement and lime stabilisers.

In this research, microbially induced magnesium carbonate precipitation (MIMP) has been investigated and adopted with the goal of improving the compressive strength of rammed earth. MIMP utilises urea hydrolysis and the presence of magnesium oxide to form magnesium carbonate, which creates cementitious bonds within the soil matrix. By adding a bacterial solution, including the bacterial strain sporosarcina pasteurii, as well as varying urea and magnesium oxide concentrations into rammed earth, it’s proposed that the engineering properties, with the focus on compressive strength, can be improved.

After conducting multiple experiments following this methodology, it was found that the compressive strength of the tested rammed earth specimens improved by almost 2000% when the maximum amounts of urea and magnesium oxide were present in the rammed earth in comparison to the controlled samples with no urea or magnesium oxide. Along with further supporting evidence provided and discussed throughout the report, it can be concluded that magnesium oxide can act as a binder, as well as form magnesium carbonate within the soil matrix due to the presence of urea, to improve the compressive strength.

This results in a more stable and strong rammed earth structure. These findings provide significance for the ability to further research this technique and broaden the scope to other soil types, as well as investigate how MIMP effects other engineering properties within rammed earth. It can be concluded that stabilisation and strength improvement of rammed earth structures can be done via MIMP and should be investigated further and promoted to encourage the use of more environmentally friendly stabilisation alternatives.

Cameron Birkholz is an undergraduate student at Curtin University who is completing his final year of Civil and Construction Engineering. Having received a Summer Vacation Program placement with Lycopodium in December 2024, Cameron has continued to work with the company on a part-time basis during 2025, as a Trainee Project Engineer, whilst completing his final year of study. Cameron will transition into a Structural Engineering role with Lycopodium in a full-time capacity in the new year.