Founding piles on the Hallett Cove Sandstone in Adelaide: A case study

The majority of the more recently constructed buildings in the Adelaide CBD are founded within the very stiff to hard Keswick and Hindmarsh Clay, because these strata are relatively homogeneous. This Paper describes the work recently undertaken for a 21-storey office building founded on the underlying more variable Hallett Cove Sandstone formation. Founding piles within the Hallett Cove Sandstone meant fewer piles carrying higher loads could be used than for piles founded in the overlying clay. However the variable nature of the Hallett Cove Sandstone presented several challenges that needed to be overcome.