Dyers Pass Road - Governors Bay - Infrastructure Repair - Overview

Works Begin 02 Mar 2015 Works End 07 Aug 2015
Works Status

This notice is an update for an earlier notice [1].

Where we are working

Map 1: Location of work. Sourced from LINZ data, Crown Copyright reserved. Retaining wall one (yellow): Dyers Pass Road (near 1093); Retaining wall two (dark blue): Dyers Pass Road (a location between wall one and three); Retaining wall three (purple): Dyers Pass Road (near 1091, which is near the intersection with Governors Bay Road).

What we are doing

  • Fletcher Construction will be the delivery team (as part of the Stronger Christchurch Infrastructure Rebuild Team) that will undertake the construction work to replace one retaining wall and repair two retaining walls along a section of Dyers Pass Road (between property numbers 1091 and 1063).
  • The repair and replacement work along Dyers Pass Road is scheduled to commence in the week beginning Monday 2 March 2015. Due to the nature and extent of the work the overall project is expected to take six months to complete.
  • Our usual hours of work are 7.00 am to 6.00 pm, Monday to Friday, with weekend work if required.
  • All of our work is subject to favourable weather and on-site conditions with this in mind we ask that you please be aware that timeframes may change.

The Dyers Pass Road Retaining Walls

The retaining walls we are repairing are constructed from gabion baskets. We will be drilling rock anchors through the gabions and installing waler beams along the face of the gabion baskets | Diagram showing rock anchor and waler beam installation | Example of rock anchors being installed through sleeve in existing gabion wall.

We will be replacing the existing timber post and panel retaining wall in the central section with a mechanically stabilised gabion wall. Example of a gabion wall being constructed.


Diagram showing rock anchor installation work through a section of gabion wall.

Stages of work

Stage one

This stage will involve the setting out of the traffic management, including the installation of temporary traffic lights. Fencing will be erected around the site to enclose the work area. Temporary speed bumps will be installed in the live lane to ensure traffic travels at a safe speed and that it is a safe environment for the crews to complete the work. During this stage the services and utilities will be protected by locating and relocating them temporarily.

These works are scheduled to commence late February 2015 / early March 2015.

Stage two

Scheduled to commence early March 2015
Repair of walls one and three

To stabilise the gabion baskets the installation of rock anchors, of various lengths, will be installed through the existing gabion baskets and into the bedrock behind. We will be installing a total of 106 rock anchors.

This work involves using an excavator mounted drill rig operating from the road above to insert a steel casing through the basket. The drill is then inserted through the casing to drill a 100mm diameter hole through the material behind the basket.

Once the holes have been drilled we will begin to complete work to install the anchors. This involves inserting the steel bar (anchor) into the drilled hole and grouting in place.

After this is completed, work will be underway to repair the gabion baskets. Final work will involve installing steel waler beams along the face of the gabion baskets.

The work will commence at the northern point of wall one and progress south along wall one, moving onto wall three when wall one is complete (see Map 1 for location of walls).

Image showing bulging gabion baskets. Rock anchor installation will pull the rocks and baskets back towards the walls.

Stage three

Commencing the same time as stage two
Replacement of wall two

Construction to replace the existing timber post and panel retaining wall (see Map 1) will involve removing the existing guardrail barrier, the pedestrian handrail and footpath. The existing timber wall will be deconstructed and dug out. Preparation work will be underway to level out and compact the ground, and a new drainage system will be installed. Work will then be underway to construct the new gabion retaining wall, this will involve laying out the gabion baskets, folding them into shape, tying the connections and filling the baskets with gabion rock.

Two photographs. Example of tying gabion baskets together (left), Example of gabion baskets being packed with rocks before installation (right).

Once the baskets have been filled and installed, the crew will then backfill behind the retaining wall in layers. The concrete for the new footpath will be poured and connected to the top of the new retaining wall. The final phase of this work will include installing a new handrail to the side of the footpath and the area immediately beneath the retaining walls will be landscaped.

Stage four

Scheduled to commence late July / early August 2015

Following completion of the retaining walls, the road surface will be repaired on the even-numbered (southbound) side of Dyers Pass Road.

Following the road surface reinstatement on the even-numbered (southbound) side of Dyers Pass Road, repairs to the concrete storm water channel will be underway on the odd-numbered (northbound) side of Dyers Pass Road. The temporary traffic lights will be uplifted at this time.

Two photographs. Images showing repairs to be undertaken to concrete storm water channel.

Traffic impacts

Traffic impacts stage one, two and three

Temporary traffic lights will be set up along Dyers Pass Road from the intersection with Governors Bay Road running 400 metres north. Temporary speed restrictions and speed bumps will be installed to slow traffic along this section of Dyers Pass Road.

Residents living within the work area will have temporary traffic lights installed at the bottom of their drives for exiting onto Dyers Pass Road.

Turning restrictions will also be in place while the retaining wall repair work is underway. Residents within the work area will not be able to turn right. We ask that you please adhere to our traffic signals and take care when exiting your driveways.

Traffic impacts stage four

A progressive shoulder closure will be in place around the work area.

Map 2: Traffic impacts. Sourced from LINZ data, Crown Copyright reserved. Temporary traffic lights: Dyers Pass Road (at the intersection with Governors Bay Road, and northeast of the intersection with Governors Bay Road); Traffic flow (red left-right arrow): along Dyers Pass Road (between the temporary traffic lights): No right turn: from the northern, northwestern, and western sides of Dyers Pass Road (into Dyers Pass Road) (between the temporary traffic lights).

General Information

Cyclists will be required to merge with traffic flow and adhere to all traffic management in place. Please follow our signs and reduce your speed.

There will be no on-street parking available along this section of Dyers Pass Road while work is underway.

Rubbish and Recycling

For residents within our work area, we would like to ask that you take your City Council rubbish and recycling bins out to the bottom of your driveway before 5:00 pm on Tuesday and we will move the bins out of the work area for collection on Wednesday morning and return them to your property after they have been emptied.

Please ensure your bins have your house number on them so we know which properties to return them to.

Work may result in increased dust, if there is dry weather conditions. The work may result in low volume noise and vibrations due to the heavy machinery used. We will try to keep any disruption to a minimum and we apologise in advance for any inconvenience.

Work may have an impact on water, telecommunication and power services. Where services are to be shut off a separate notice will be delivered to affected residents prior to any planned shut off.

Due to the nature of the work and for safety reasons, the footpath above the work area will be closed. Pedestrians will be escorted and access will be maintained via a temporary footpath.

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

If you have any questions, or for any other information about this work, please contact Fletcher Infrastructure on 0800 444 919 from 8:30am–5:00pm Monday to Friday and we will be happy to help you. You can also contact us by email: CIRinfo@fcc.co.nz [2]

Thank You

Fletcher Infrastructure on behalf of SCIRT (Stronger Christchurch Infrastructure Rebuild Team) would like to take this opportunity to thank the Clifton community, especially directly affected residents, for their patience, support and cooperation while we complete these works.


Start date: 
Mon, 02/03/2015
End date: 
Fri, 07/08/2015
Project numbers: