Residential

Project Examples 7 to 9

Mandurah Marina & Esplanade 

The Mandurah Marina and the Esplanade hosts a variety of commercial and luxury residential developments. This canal based boardwalk subdivision called for special foundation considerations due to estuarine silts and sea-wall surcharge restrictions.  Subdivision engineers design canal sea-walls with consideration for the future structures that will be constructed above or near it. Final design specified a set of criteria for any future construction. The specification sets out a construction easement and any allowable surcharge loads.  Builders contacted Screwpile Australia for economical foundation solutions which prevented any surcharge loads impacting sea-walls.
Sites either consisted of dredged engineered fill and estuarine silts. Layers of geotechnical fabric grid such as Tensar were installed behind the walls. Any piled foundation solution could not compromise the performance of the grids. Screwpiles had the unique ability to simply cut a small slice through the Tensar as the pile wound past on it’s way to the required founding depth.  A piled solution needed to transfer construction surcharge loads to below a line of influence from the sea-walls foundations.  Screwpiles were designed and installed to a depth which exceeded any zone of influence and in accordance with the geotechnical capacity for the site. Screw piling depths varied from 4.0m through 23.0m.

Iconic Structures

Screwpiles are often specified for these structures simply because of speed of installation and economics.  Structure installations may be in challenging locations or poor grounds or subjected to high wind loads.  There is no other foundation system that can compete with screwpiles with respect to the versatility, speed of installation, none-disruptive eco-sensitivity and cost effectiveness.

Renowned sculpture artist and bronze figure casting expert Mr Charles Smith along with renowned consulting structural engineer Mr John Colley have engaged Screwpile Australia on a number of occasions to design and install screwpiles to support their sculpture projects in locations of loose soils and high wind regions.

Projects such as:

  •  The stainless steel seagull dome of the HMAS Sydney Memorial Site located high on the windy sand dune escarpment of Geraldton, WA.
  • Burswood Casino Lake Bronze Swan Sculpture where deep piling was needed in the lake without damaging the lakes waterproof membrane.
  • The Willem de Vlaming Memorial Sundial which sits on loose swan river silts.

Multi-Story Apartments with Basement

This new Psaros development in Highgate required tanking of an underground basement carpark. The site needed to be sheetpiled and have over 85 combined 500kN SWL compression/tension screwpiles to cater for the hydrostatic uplift and construction loads.  The tension component of the piling was to prevent the basement from lifting once the dewatering was turned off and the next construction phases commenced. Compression loads would develop as construction continued.

Sheetpiles were installed to the perimeter of the proposed buildings walls. Dewatering spears were installed so that excavation could be completed to below the lift shaft below the proposed basement level.  Once excavated the 50 tonne screwpiles were installed to a depth of 6.0m below basement & lift shaft levels. A load testing régime was put in place. Compression and tension ISL load tests were conducted and recorded to confirm pile load capacities. Test results confirmed screwpile performance was in accordance with engineering design.
Screwpiles were concrete filled and pile to pilecap interfaces were constructed to accommodate the dual loads. A backing out method of installation allowed for the immediate forming and casting of concrete pile caps minimizing any potential construction sequence delays.