5 BED | 7 BATH | 4 CAR
STUART OSMAN BUILDING DESIGN
Set on a 3149m2 main river site in Carrara, this large family home with a detached Billiards Room was expertly designed to maximise impact and intuitively manage building costs. The house is underlain by compressible marine clay that is subject to significant settlement when loaded. To achieve the necessary flood level, the project also needed to be raised approximately 600mm above the original ground level. Geotechnical testing identified that 600mm fill would induce 70mm of long-term settlements on top of the settlement from the house structure. While the most common solution in this situation is to pile through the weak compressible soil layers to reach a competent stratum, the 12-15 metre depth required on this site would have cost approximately $100,000. To reduce construction costs, Icon Consulting Engineers collaborated with specialist geotechnical engineers to design a high-level structural raft slab that floated above the weak compressible soils and eliminated the need for deep piling. This was achieved by replacing the weight of the 600mm fill with light-weight void farmers throughout the slab to create a deep stiffened raft slab and reduce the proposed development’s total load to 20 kPa.