Abstract:
As urban development expands into sites with complex ground conditions and physical constraints, increasingly sophisticated engineering solutions are required to resolve construction challenges. In Melbourne’ s Docklands, a high-rise residential development has been proposed along a historic wharf site bounded by the Yarra River to both the north and south directions.
The project required deep foundation piles to support the structure, as well as a retention system to facilitate core excavations. Given the site's history as reclaimed land and its proximity to the water in very soft soils, significant physical and geotechnical constraints influenced the design and construction methodology. Subsurface conditions included soft soils, a variable-thickness basalt tongue underlain by weaker soils, and deep siltstone, all of which posed substantial design and construction challenges.
This paper will cover the formulation of the foundation and retention design solutions and the appropriate selection of the piling equipment/methodology to control the lateral soil movements during piling installation. This paper explains how the considerable risks to both the existing wharf infrastructure and the piles themselves were minimised during the construction process. It will also provide an insight into the extensive dynamic testing program that had to contend with variable founding conditions across the site.
The paper demonstrates how a multi-technique design-and-construct approach incorporating CFA piles, driven precast concrete piles, driven steel tube piles and sheet piles enabled a safe, efficient, and technically successful outcome for this complex urban project.