Alfred Hospital Main Ward Block, Prahran VIC (1969 to 1977)

As well as being the largest project undertaken by Hansen Yuncken at the time it was built, the Alfred Hospital Main Ward Block incorporated a major innovation in its foundation. The site's sandy geology posed problems because the design called for an excavation to a depth of 10 to 12 metres, but the ground water surface level was at about three to four metres.

Max Hansen said "We used a well point system around the site to suck water out of ground and drain it before excavating narrow, deep trenches with a purpose-built excavator, which were then progressively filled with Bentonite slurry. We then used massive precast panels - we had the biggest mobile cranes in the country at the time - that were dropped into the ground through the Bentonite slurry. Then we worked around and tied the whole lot together, so the bottom formed a solid concrete raft about 2.5 metres thick at a depth of 12 metres. It was designed to settle as it got bigger, and it settled about five to seven centimetres overall. An ordinary steel-framed building sits on top of the raft."