Humphreys Drive - Woolston - Retaining wall replacement

Where we are working- Humphreys Drive

Map 1: Site Plan     Sourced from LINZ data, Crown Copyright reserved

What we are doing

• We are removing and replacing the partially collapsed retaining wall on Humphreys Drive near Linwood Avenue. It is being replaced with a structurally designed, gabion basket retaining wall (see photo and description over the page). Geogrid textile* will extend into the embankment to hold the new wall into position. The new wall will be constructed in the same position as the previous wall with the inclusion of safety barriers and fencing.
• A temporary propping system has been designed to eliminate the potential risk of collapse of the wall during construction.
• We will be working Monday to Friday between the hours of 7:00am to 6:00pm. On rare occasions we may have to work weekends to complete essential work.

 *Geogrid textile is a material commonly used to reinforce retaining walls. It is made up of interwoven materials such as polystyrene or polyester.

What is a Gabion Basket
 

• Gabion basket retaining walls provide a structurally sound way to stabilise shorelines or slopes against erosion.
• Gabion basket retaining walls are a good solution as they move with the ground when the ground moves, they drain water freely and they dissipate the energy from flowing water.
• Gabion basket walls also increase in strength and effectiveness over time, as silt and vegetation fill the smaller voids and reinforce the structure.

Traffic Management:

• Humphreys Drive will remain two way past the work site, however speed restrictions will be in place.
• Please be on the lookout for changed traffic conditions and drive to the conditions.

General Impacts:

• We will be sheet piling around the work site while work is taking place. The sheet piles will act as a barrier against any discharges, either from machinery or work from the excavation, which could work their way into the estuary.
• The work will have no impact on water, power, telecommunications and wastewater services.
• The work may result in increased dust, noise and vibration.
• We will endeavour to keep any disruption to a minimum. We apologise for any inconvenience and appreciate your  patience while we do this work.

General Information:

• Safety is our number one priority. Safety is also your responsibility too. Please make sure you stay clear of works, stay alert and keep children and pets at a safe distance.

Need more information?

If you have any questions, or for any other information about this work, please contact Downer on 0800 400 310 from 8:30am–5:00pm Monday to Friday and we will be happy to help you. You can also contact us by email at eqinfo@downer.co.nz