A remote location, soaring temperatures and a challenging environment couldn’t stop Keller successfully completing piling works for a unique project at the Cloudbreak mine – 10 days ahead of schedule
Engineering and infrastructure company RCR Tomlinson is constructing an A$33 million, 5km-long relocatable conveyor system at the Cloudbreak iron-ore mine in the Pilbara, Western Australia.The innovation is a key piece of technology for Cloudbreak and other mines in the region run by the Fortescue Metals Group.
With huge experience of working in this remote part of the country on numerous mining projects, Keller Australia was appointed to install foundation piles for key sections of the pioneering new system.
Logistical challenges
"We started on site in early March and the works were divided over three 30m areas where the conveyor needed foundation support,” explains Project Manager Mo Aziz. “After carrying out point load index testing to verify the required rock socket depth, we carried out the works, which consisted of 18 bored piles with temporary segmental casings over the three areas. The piles were of various lengths, with diameters of 1.2m and 750mm.”
Although the scope of works was relatively small, Mo says the project was not without its challenges. “Logistics is the big factor,” he says. “It’s very remote there so you have to be so well organised in terms of equipment and being prepared for any potential problems.
“It’s very hot and humid and it rains pretty much every day at around 11am. At that point you can’t do anything. Temperatures can reach around 45 degrees and once it gets to 37 degrees you can’t pour the concrete. We had some issues with the concrete supply, which had an impact on when we could work, but we were prepared and able to mitigate the problems.
“The site is inside an existing 10-year-old active mine. Some of the challenges we faced were the unpredictable subsurface conditions and operational constraints of the mine. We had to be certain that our drilling equipment, construction methodologies and associated resources could achieve the outcomes we planned for.
“On one occasion we had to wait at least three days for some of our piling gear to arrive from our Queensland yard as there was a severe weather event that led the driver to detour the route twice. The rental company we used for the hire of utes couldn’t get to the site due to heavy rain, so they had to drop them off 100km away!”
Excellent performance
With huge experience of working in the Pilbara, the Keller team had contingency plans in place and in the end completed the works in just 17 days – 10 days ahead of schedule.
“The client was very happy with our performance and the fact that we were able to complete the piling works ahead of schedule,” says Mo. “The quality of work was high. For example, we successfully constructed one pile with critical positional tolerance with a cast-in-place ‘top hat’ holding down arrangement. This pile and connections to top structure has maximum positional tolerance of 10mm in any direction with a plus or minus tolerance of zero and 10mm.
“This project shows that whatever the size of project, we don’t underestimate anything and always strive to offer the same high levels of detailed planning and service.”