City of Belmont Car Park Design – undeveloped road reserves

Two car parks, N & S. Both are 12m wide x 40m long with x16 parking bays each.

A narrow, 3m-wide strip of open ground along the north side lies in-between the hardstands of the Council carpark and adjacent industrial land of both carparks.

Trees to be planted in centre of strip, six (6) trees per carpark (i.e. 1×3 bays): sp. Angophora costata

Carpark North (control)

• Total surface permeable paved. Product: Midland Brick’s ‘aqua tri-pave’, being a copy of Adbri’s ecotrihex
• Over 50mm depth bedding 3–5mm dia. aggregate
• Geotextile
• Over 300mm depth 20–40mm dia aggregate
• Over in-situ native soil (sand), lightly compacted
• Kerb on conventional road base with 300mm ribbed root barrier against back of kerb (RER 300’) 

Carpark South (custom soil)

• as described above except:

• Geoweb / cellular confinement system at 200mm depth to hold screenings

• Underlying soil: no compaction other than perhaps one run-over with plate compacter to smooth ground level

• Eight (out of the 16) parking bays in which the in-situ sandy soil is replaced with a custom mix of higher fertility

• Spray-on root barrier at back of kerb (instead of a rigid barrier)

• Vertical steel rods to identify and compare oxygen content between in-situ & custom mix in subsequent years

Measurements:

• Soil analysis (organic content/fertility, Ph) and infiltration rates (hydraulic conductivity) in 4 locations per site

• Annual canopy growth

• Settlement of pavement

Rationale:

The intent is for a design which factors the hardstand as a fully functional proper root-zone, in order to maximise the canopy potential and minimise the likelihood of pavement displacement.

The custom-soil is to be a cost/benefit analysis.  Comparing canopy performance correlated with the monetary amenity values.