The Huntly section of the Waikato Expressway project will soon have its own quarry providing rock to the roading project. By MARY SEARLE BELL.
As part of the project works, a massive 57-metre-high cut at Taupiri Pass will see 1.2 million cubic metres of earth removed from the mountain range.
The material from the cut will comprise 500,000 cubic metres of greywacke clay, much of which has been removed this summer; 400,000 cubic metres of weathered rock, which will be used as bulk fill in the project; and, finally 300,000 cubic metres of hard rock.
This rock will be blasted and processed on site by a mobile crusher as 150mm all-in rock. It is to be used as subgrade improvement material on the project.
Project director Tony Dickens, from Fulton Hogan, says they are yet to seek a subcontractor for the quarrying work, but will be inviting tenders during July and August this year.
“It will be a critical activity for the project,” Tony told Q&M. “There will be a high rate of production and good cooperation needed to coordinate the road construction, rock extraction and rock processing all at the same time.
“It is very much a roading project and it will not be your typical quarry operation. We have to take anything that comes out of the excavation and make the best of it, rather than selecting only the best rock to use,” he explains.
“We’ll have to stockpile along the narrow roading corridor too.”
The entire Waikato Expressway will see a four-lane highway constructed all the way from the Bombay Hills, south of Auckland, to Cambridge – a total distance of 102 kilometres. The project is being delivered in seven sections, three of which are complete.
The Huntly section of the NZ Transport Agency’s Waikato Expressway project stretches for 15.2 kilometres, from the Ohinewai section south to the Ngaruawahia section, and will see a busy part of State Highway 1 move away from the township of Huntly. The quarry at the Taupiri Pass is roughly in the middle of the section.
Earthworks are in progress on the Huntly section. It has been a challenging season for the Fulton Hogan-HEB joint venture, with the weather doing its level best to slow things down. The goal is to move 2 million cubic metres this season, and Tony says they are well on the way to achieving this goal.
However, with three weather events so far this year, it seems unlikely they will reach this target before the earthworks season finishes.
“The reality is we have 30 more earthworks days ahead of us and only 33 days left in the summer season,” he said in mid-March. “Getting 30 dry days out of 33 is impossible – we’ll have to work harder next year!”
Fortunately, says Tony, as it’s a four-year-long project we have room to adjust.
“Our critical path is still intact.”
The Huntly section, and the whole Waikato Expressway project, is due to be completed in 2020.