Keller completed earth retention and foundation works in challenging soil profiles for a luxury aged care facility Sponsored

The growth in demand for aged care facilities in Australia has led to an increase in private developers entering the market. One such developer is Oryx Communities, which is building luxury aged care apartments in Claremont, a suburb of Perth in Western Australia. Keller was involved at an early stage of the Queenslea project, selected by main contractor Multiplex to design and construct a piled retaining wall and foundation piles for the proposed building's column-bearing loads.

The main part of the project called for a wall to retain a one-to-two-storey basement in a site roughly 45m by 70m. The biggest obstacle of the project was the ground conditions, which mainly comprised sand but with a high presence of limestone.

"This precinct is fairly notorious for limestone pinnacles that are highly variable in presence and strength. Limestone can have a very detrimental effect on pile constructability, causing problems with verticality and piles encroaching into the basement footprint. A quick look at some of the other buildings nearby shows you the problems other contractors have had. At the end of the day it was all about taking our time and meticulously and repetitively checking the drilling verticality of the machinery to ensure we were adhering to performance requirements," explains Brad Clothier, Project Manager.

"We wanted to use the most economical solution possible that would still provide all the necessary retention characteristics. With this in mind, and given the depth and soils, we designed a partially anchored, partially cantilevered solution with small mechanical anchors in some locations. In total we installed around 400 retaining wall continuous flight auger [CFA] piles. Alongside this we also installed 200 CFA foundation piles to a depth of 10m to support the structure, " he adds.

"This project has shown that Keller people have the skill set to manage risk in challenging soil profiles and work in constrained spaces to design and execute a successful project," says Brad. Having started on site in July, the team finished in September, well ahead of schedule, with no quality issues and a very satisfied client.