From earthworks to pavement

Large sections of the project are transitioning from earthworks to pavement construction.

As the earthworks team digs through ridges and under bridges in the north of the project, the stronger ash soils have been spread and compacted to form embankments for the expressway. Weaker soils are used to form the slopes on either side of the embankments, or for landscaping. Sand is then laid as the final earthworks finishing layer.

Over this winter and into spring, our earthworks team will begin handing over long sections of the project to our pavements team to begin laying aggregate to build the road. It’s important that the earthworks team has completed their work before handing it over, because if dirt is tracked on top of pavement aggregate, it may weaken the pavement layers.

Click the graphic to see a timelapse video of pavement construction near Kay Road.

Lots going on in the gullies

The southern gullies between SH1-Cambridge Road and Matangi Road are one of our busiest sites right now.

Our soil nail team is drilling holes for another layer of soil nails. They drill an 8m deep hole, insert the nail, concrete it in place, screw on the washer then test for strength. The rolled strips are drains that unroll as each layer of soil nails is placed. These nails and the steel mesh stabilise the slope.

Our piling team is driving new foundations for the two bridges over the Mangaone and Mangaharakeke Gullies.

A specialist team is mixing cement with the soil up to 3m deep, where the Cambridge Road Bridge (onramp to the expressway) will be constructed. Usually, a deep layer of compacted rock is used for this purpose, but this is not possible here because the water table is too high.

Planting has begun

Planting is under way in various locations where embankments have been finished with topsoil and mulch. We will plant 160,000 plants this winter. Most are native species grown from seed sourced in the Waikato. Click the graphic to see how it’s done.

Progress at the Matangi Road Bridge

The Matangi Road Bridge was blessed this month in a ceremony organised by our Tangata Whenua Working Group. The dawn blessing was carried out before traffic began crossing the bridge.

More information

For more information on the Hamilton section of the Waikato Expressway, contact us at waikatoexpressway@nzta.govt.nz or phone us on 0800 322 044.

Visit our website www.nzta.govt.nz/hamilton