Building on 45 years of Engineering excellence, Advanced Substructures delivers the very best substructure designs in Australia.
This page details benefits consistently delivered by our industry leading techniques on ground-breaking and award-winning projects.
Top Down Construction
One of our key techniques for accelerating construction, reducing cost and materials use, and creating the best use of spaces above and below ground, even in sensitive or access restricted areas.
Here is how it works :
Cost and Time Savings
We have completed a fully costed study showing our techniques save
up to 38% on construction costs and a minimum of 13% build time over conventional methods for a single level, 144 bay underground car park. More details are in the brochure (click on the red button) :
Piles to Pillars
Recently awarded an Innovation Patent, we consistently achieve thinner visible pillars through this technique. It maximises the usable space for parking or any other application. .
It works by (see left, below) :
1. Encasing a steel corseted central pillar within the concrete pile at the same time that the top-down construction retention structures are cast
2. As the substructure is excavated, the concrete piles are revealed
3. When the excavation to form the basement is completed, surplus concrete is debonded from the steel corset revealing the finished column
4. Piles formed can be circular, rectilinear or square - and routinely measure around 350mm in diameter.
Thinner rafts without footings
Our techniques minimise the thickness of the lowest level concrete raft by using post-tensioned concrete and our system of horizontal propping; which reduces the risk of cracking and leakage by the exothermic heating of concrete in the damp underground setting.
Top-down construction enables the use of this technique.
The need for footings and formwork is significantly reduced by the use of retention structures and columns/piles cast prior to excavation.
Waterproofing without membrane
Unique to Advanced Substructures is our design that enables waterproofing of the substructure without the requirement of using a waterproofing membrane. Waterproofing membranes have been shown to be largely ineffective in the prevention of ingress of waters into substructures at depth.
Our system efficiently uses available material technologies to create a waterproof seal without this material, even far below the water table.
Our techniques yield significant :
Capital cost savings
Time savings due to simultaneous construction of substructure and superstructure
Materials savings due to elimination of formwork, footings, column cladding and other elements
Increase in usable and saleable space
Earnings improvement through earlier availability to tenants
Reduction of risk via
Proven design techniques, controlled operations and extensive quality measures
Minimised risk of leakage or cracking on wet sites
Minimised disturbance to adjoining properties due to soil movement or propping
Minimised traffic, dust and other environmental disruption to surrounding area as construction occurs under "lid" slab
Removal of excavation from critical path in construction
Elimination of need for a below-ground pit prior to superstructure construction
Removal of need for sheet piling or other temporary measures
Elimination of formwork from the ground level down
Substantial reduction of thickness and depth of retention structures required
Excavation is enabled on sites where tieback installation is not feasible and soil movement must be minimised
Reduction of concrete used (with reduced carbon footprint and cost savings)