Peacocke Whatuaooruru Drive Ring Road Project
We are engaged by Downer as part of the bigger Peacock Development programme as the Earthworks Contractor for the large excavation of foundation works. This required excavating 9 meters down into a gully and constructing a load transfer platform consisting of geotextile, grid, drainage, and aggregate to be compacted to specification.
Client: Downer
Contract Value: $500,000 - excluding materials
Timeframe: Feb 2023 -> Expected Completed June 2023
Project Type: Earthworks Contractor to Downer
Location: Peacocke, Waikato
Pecocke is constructing a new community neighbourhood as part of Hamilton City Council's to grow Hamilton by building a new neighbourhood to accommodate more than 50,0000 people expected to move to the area. Peacocke is Hamilton's largest greenfield area.
Downer is contracted to build a new ring road to connect the Peacocke neighbourhood and the new river bridge under construction as part of this project. Downer has subcontracted us to complete the earthworks. The work comprises of bulk earthworks and technical detail for building retaining walls relating to the access and construction of the bridge abutments.
The work included boxing and pouring concrete slabs ready for mass blocks weighing about 2.5t to be placed accurately in line and level. Once blocks were in place, we backfilled behind these blocks with aggregate and grids to hold the blocks in place. This continued until the wall was at height, and in places, the wall was 9m high. Each abutment was an excavation of about 4,000m3 and then backfilled with good material GAP65 again. Backfill for these walls had to be done systematically and methodically to not overload the wall and ensure that all tests like NDM (Nuclear Densitometry) were passed.
This project requires an element of technical earthworks that needs to be completed, similar to TDC EUL. There are also structures with the 2.5m box culvert that will need some specific and systematic methodology to ensure this is constructed in a manner that will not cause any failures but ensure all things are passed and ticked off step by step.
On two of the walls, when we got to the bottom of the excavation, we encountered soft and unsuitable ground conditions, which were highlighted to us by the Geotech Engineer once testing at the base was undertaken. We overcame this problem by undercutting the area by a further 500mm and replacing it with geotextile and grid and good clean material (GAP65). Our site team worked closely with a nearby farmer to ensure he had unfettered access to his farm, allowing the farm to continue without disruption. This assisted the team during earthworks as there were several times we needed to work with the farmer to shut off his water to complete connections for the main water line.