Leading design and construction geo-technical specialist Menard Oceania have been awarded the ground treatment and preparation work for two Sydney Metro City and Southwest station sites – Barangaroo and Waterloo.
At the Barangaroo Station site, Menard will cut-off ground water flow ahead of excavation. Menard works at the Waterloo Station site comprise of installing more than 1,000 anchors and rock bolts for the station box.
Working on behalf of the tunnel and station excavation contractor JHCPBG (John Holland, CPB Contractors, Ghella), Phillipe Vincent, managing director of Menard Oceania, and recently-made Fellow of Engineers Australia, said Sydney’s geology is unique with one of the world’s best stratum for tunnelling.
“With over 45 years of experience in the city, we understand local geo-technical conditions and use innovative and cost-effective techniques to re-engineer poor soils and weak rock formations into solid foundations,” Vincent continued.
“This award further reinforces Menard as a dominant player in Australia on complex infrastructure projects.
“Right now, my focus at Menard is to continue leveraging our deep expertise across a diverse range of infrastructure projects and geologies to expand our share of the market. We’ve had a strong year to date and I look forward to building on this even further in the months ahead.
“We are definitely looking at growing the market and on leveraging the solutions and the talent that we have to complement our offering to our clients.”
Sydney’s foreshore geology mix includes Triassic Hawkesbury Sandstone and Ashfield Sandstone with varying degrees of weathering, within deep alluvial soils. In places, a high ground water table is also present which requires specific mitigation measure.
Also, for the Barangaroo Station site, which is in close proximity to the harbour, there were challenges in terms of dealing with water flowing in during the excavation process.
“As part of the project, we developed some innovative ways to transport and deliver the 1,000-plus anchors we have been contracted to produce to site,” Vincent said.
“The anchors are built to state-of-the-art quality standards in our in-house Sydney warehouse facility.
“They are then transported to site using an innovative bundling system, which enables automatic feeding of the anchors in the drilled holes, thereby reducing manual lifting and handling, and as such, pre-emptively improving safety performance.
“It is a permanent focus for Menard to participate in the improvement of industry safety standards and ensure all of its staff, as well as other workers and members of the community remain safe.”
Because of the inherent unpredictability of geo-technical conditions on a project, principals and consultants cannot completely eliminate these risks. However, with a blue-chip geo-technical team, principals and consultants can confront the risks head-on and keep them under control.
According to a recent white paper from Menard, which offers some insights for principals and consultants on best practice for hiring the right geo-technical team, there are five things one needs to make sure is being done. They are:
- Investing time upfront to select the best team for the job;
- Understand the project risks first to determine the best solution;
- Establish clear communication and collaboration with full project team;
- Be flexible and responsive to changes in site conditions; and
- Apply consistency in approach to site inspections and peer reviews.
“Whilst there are a number of different sources of risks, it often starts with the geo-technical assessment associated with the specification of the project, and later the implementation of the foundation works,” Vincent said.
“Risks associated with unexpected ground conditions due to natural variability or man-made buried contamination and obstructions are responsible for more claims than any other project scope item.
“Earlier involvement of geo-technical contractors is paramount in making sure that the challenges are taken into consideration right from the beginning of the development of the project.
“We find that we generally have much better success if both the geo-technical consultant and the contractor, as well as all of the structural, building and all other contractors are all heavily involved and given the chance to sit around the table to discuss the challenges, opportunities and solutions available.”
Sydney Metro City & Southwest extends the new metro network from the end of Sydney Metro Northwest at Chatswood, under Sydney Harbour, through the CBD, and west to Bankstown.
JHCPBG is building the 15.5km-long twin railway tunnels between Chatswood and Sydenham and excavating six new metro stations.
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