Completion of a new stormwater pipe under SH2 in March required working in a deep excavation close to live traffic and services such as gas, sewer and fibre optic.

What happened in March

Last month work continued around the Maunganui-Girven intersection and along State Highways 2 and 29A, near Baypark.

This work included:

• Installation of a new stormwater drain under SH2, between Matapihi Road and Bayfair Shopping Centre completed.
• Earthworks started along the southern side of Matapihi Road and temporary traffic management installed.
• Progressed earthworks for the new northbound on and off-ramps at the Maunganui-Girven intersection and new SH29A roundabout.
• Installed instrumentation in the empty sections along Maunganui Road, in preparation for the construction of a trial embankment.
• Power and gas relocation works continued along SH29A and SH2, and the new sewer line connections were completed, including ducting for services near the Maunganui-Girven intersection.
• Locating and protecting underground services.

The works around Harris Street and Bayfair Shopping Centre are part of the Bayfair expansion and not related to this project.

With the Matapihi Road widening starting, temporary changes to the traffic lane and footpath alignment will remain in place for about six months. The new work areas do not affect access to local businesses who continue to operate as usual.

What to expect during April

During April the focus will continue around the Maunganui-Girven intersection and State Highways 2 and 29A.

You can expect:

• Earthworks will continue along Matapihi Road and on the new northbound on and off ramps at the Maunganui-Girven intersection in preparation for pavement works.
• Construction of a trial embankment in the empty sections along Maunganui Road.
• Temporary traffic management will continue to be extended along SH29A, between Baypark and the Te Maunga intersection, moving traffic closer to Baypark.
• Importing of pumice fill will finish and road construction will begin for the new SH29A roundabout.
• Relocation of utilities and installing new ducting will begin along Matapihi Road and in the SH2 northbound verge, between the Te Maunga intersection and Concord Avenue.
• Service relocation works will continue with the installation of a new gas line in the south. Relocation of power near Truman Lane will be completed and will then begin near Exeter Street.

A 50km/h temporary speed restriction is in place throughout the site for the duration of the project for the safety of drivers and their passengers, and also for the people working on the project. Please take care driving through the site.

Core samples have been taken to understand the trial embankment ground conditions, to a depth of nearly 40 metres.

Trial embankment

As part of the design process, a pre-load trial will be carried out in the empty sections along Maunganui Road to gather further information, primarily compaction and settlement rates, about the soils the Bay Link embankments will be built upon.

Building a road requires a firm base and it needs to be stabilised slowly, via a process called pre-loading. Adding layers of dirt (fill) on top of the soil will compress the ground, which will reduce the risk of sinking in the future. Compressed soil helps to keep the road smooth and flat for the surface to be laid on.

In April, the embankment will be constructed from soil within the work area and stand approximately six metres high by 30 metres long. It will take about three weeks to complete, at which time it will be wrapped in plastic to avoid issues with erosion and dust, and secured with a temporary fence for the nine to 12 months it will be in place.

Trialling a new product to black-out old road markings so they will not become visible to road users in any weather conditions.

Removing road marking

During construction, traffic will need to be moved temporarily and new line marking installed to guide motorists safely through the project area.

To avoid confusion for motorists the existing line marking is removed or blacked-out. An important aspect of doing this is to ensure that the lines do not become visible again when the road is wet or the sun is at certain angles. This is often referred to as 'ghost marking'.

To eliminate ghost marking we have tried various methods including black paint and hydroblasting to completely remove lines. We are now testing a further option of a slurry mix on different surfaces across site.

While we work to find a solution please drive to the conditions and keep to the 50km/h temporary speed restriction that is in place throughout the site.

Contact us

For more information on the Baypark to Bayfair Link upgrade project, contact us baylink@nzta.govt.nz

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