The two initial projects were completed successfully and ahead of schedule with no significant safety incidents. They have led to contracts on three more level crossing projects in recent months, involving continuous flight auger piles, a bored secant retaining wall and bored retention and foundation piles.
“There are a lot of these level crossing projects in the pipeline, which is great for the construction industry around here,” said Keller regional manager Diarmaid Long. “We’re confident that our expertise and reputation on these successful projects will lead to us winning even more in the near future.”
More than 50 dangerous or congested level crossings are being removed and replaced by 2024 in a Victoria state government initiative designed to improve public safety, speed up travel times and boost the local economy. The Level Crossing Removal Authority has to date overseen the removal and redevelopment of 11 crossings, including two each in the suburbs of Bayswater and St Albans – both of which have involved Keller.
For Bayswater, Keller was involved during the tender process, providing design and constructability advice to the delivery alliance of Laing O’Rourke and Fulton Hogan. “The overall project involved removing the level crossings and creating a grade separation for a rail-under-road solution,” said Long. “So that the client could dig a corridor over a 1km decline, they required our expertise to construct the retaining walls, which were designed to protect the property and critical rail assets immediately adjacent to the excavation.
“Before the contract award, we worked closely with the client to develop a solution over several months to help them understand what would work and what wouldn’t. Once we’d won the contract, we then installed around 900 bored retention piles (900mm and 1,050mm diameter) up to 24m deep over about eight months. This solution was the most efficient to meet the pretty tight programme constraints.”
St Albans, in western Melbourne was a similar project, won through a competitive tender put out by CPB Contractors. Keller was contracted to install retention piles for two rail underpasses and foundation piles for pedestrian bridges, a gantry and signal structures. The team installed around 500 bored piles at 600mm and 700mm diameter. While the geological conditions in Bayswater with its stiff clays were relatively straightforward, the high-strength basalt at St Albans required an expert team and specialist Bauer BG30 and Mait HR drilling rigs. These provided the necessary power and manoeuvrability on what was a tight site.
“The main challenge for both projects was that we were working in built-up areas within live rail corridors and close to the public,” said Long. “This type of work always presents numerous safety, logistic and programming challenges. Many areas could only be accessed during weekend or short-term rail occupations, where 24/7 works and up to five rigs and 10 crews were required to ensure the client could fully utilise the trains being taken offline.”