Northern Parklands Walking Tracks
- Client: Western Sydney Parklands
- Principal: Co-Ordinated Landscapes
- Date: October 2015 – Feb 2016
The contract consisted of construction of 1.5km of bitumen walking / cycleway tracks connecting Knox Rd with Richmond Rd via John McAleer Park Glendenning
After the initial site survey a few minor adjustment to the proposed alignments of the track around existing trees, fences and low lying areas were required to ensure a consistent “flow”. The next step was to strip and stockpile grass and topsoil for reuse as backfilling against the edges of the new walking track. Once the subgrade was exposed bulk excavation to reduced levels was undertaken with the use of a Cat 308 excavator and Barford articulated dump truck. The standard WSPT carpark pavement profile of 2 even layers of DGB20 120mm thick as subbase and base and 1 layer of AC10 40mm thick was used for the construction of the paths primarily with a width of 2.5m to 3.5m. The 3.5m path is to allow a suitable surface width for maintenance vehicle access.
There were several area where there was the requirement for culvert crossings ranging from 1200mm dia RCP pipes down to 300mm. Custom made concrete headwalls capable of fitting double1200mm RCP pipes were installed weighing 4 tonne each. A franna crane was used for the installation of the headwalls with the pipes being lifted in with a Cat 320 excavator.
After the bulk excavation and stockpiling a proof roll of the existing subgrade was undertaken under the supervision of our NATA accredited geotechnical engineer to determine the suitability of the existing subgrade for founding of a flexible pavement paths. The original construction details called for lime stabilization of the subgrade to a depth of 150mm at 3% application. Due to the flexibility of the schedule of rates we were able to have this item removed from the scope of works as it was determined it was not required saving the client close to 10% of the overall contract sum.
On completion of density testing and release of the relevant hold point on the subgrade the 120mm recycled DGB20 subbase and base profiles were installed. One of the major difficulties of the site during this phase was that it was one way in and the same way out. With this in mind we had to stagger bulk material deliveries to ensure our cartage contractors were not held up. In addition temporary turning bays were constructed large enough to enable trucks to turn around. On completion of the project this turning bay was “made good” and returned to its original condition.
With the subbase and base completed the tracks were graded with a 10m grader to the required max 2-4% crossfall. This allowed our asphalt contractor to lay the required 40mm thick AC10 bitumen layer to the required tolerances.
Make good to all disturbed areas and new track edges was undertaken on completion