Kia ora and welcome to the March 2018 update from the Transmission Gully team.
View looking over the launch yard with launching nose assembly underway.
Welcome to the March 2018 construction update for the Transmission Gully motorway project.
Good progress is being made on multiple fronts along the new 27-kilometre Transmission Gully motorway. Although many of these works aren’t visible to the public, significant earthworks continue, with many parts of the alignment now built up to subgrade level (the final level before road pavement construction begins). Many of the structures are now taking shape, with works on the project’s largest structure, the Cannon’s Creek bridge, building momentum.
Here’s the latest from the team on what’s been happening across the Transmission Gully project in the last month, and what’s coming up.
At the northern end of the project, near Queen Elizabeth Park, drainage works continue in preparation for the first section of road pavement to start.
We have changed the road layout on State Highway 1 (SH1), moving the lanes closer to the eastern side, so our teams can work safely on the western side of the highway. In approximately six weeks, the lanes will be moved closer to the western side to allow work on the eastern side to get underway. Keep an eye on the message boards for more information and please take care when driving through this area.
By early August, traffic will be moved over from the existing SH1 onto a new section of Coast Road to allow us to complete works to join the Transmission Gully motorway with the Kapiti Expressway. We’ll keep you updated on works and what to expect leading up to the switch over.
Reinforced earth wall construction for Bridge 2 is progressing well, with the services corridor that will run under the bridge nearly complete.
We’ve moved the barriers near our site entrance creating enough room for cyclists both north and southbound within the existing shoulder of SH1. The temporary cycle path beside the highway will now be closed so check out the map for more information, and on alternative cycle routes through this area.
Motorscrapers at work in the Wainui Saddle. This photo shows some of the larger sections of earth cuts. Soil nails, shotcrete, and green hydroseeding are just some of the techniques used to stabilise banks.
Foundation works for Bridge 3 over Te Puka Stream have started, following vegetation clearing last month.
Through the Wainui Saddle, bulk earthworks continue, with the teams making the most of the good weather. These works will continue until May, when work reduces for winter.
We’re currently focussed on Horokiri Stream diversion works, with the team set to divert the stream into another new section of permanent stream channel in early May. Work on Te Puka Stream will restart in the next month.
View looking South over a section of Horokiri Stream where earth is being deposited for fill foundation.
A 500-metre section of Horokiri Stream permanent channel now complete.
A focus for the environmental team in this area is the new habitat for the lizards that were temporarily rehomed in the Nga Manu Nature Reserve prior to earthworks starting. We are actively controlling predators around the newly created boulder fields, ready for the lizards to be returned to their new home in April.
Further south, towards Battle Hill Farm Forest Park, works continue to bring the road alignment up to subgrade level. Construction of the bridges in this area is also progressing well. A section of stream diversion works for Bridge 4 has been completed and foundation works are now underway. Recently, ‘super-T’ precast concrete beams were lifted into place for Bridge 6.
Gas pipeline relocation works are now complete beside our site compound on Paekākāriki Hill Road. This is a major milestone for the project, marking the completion of all gas pipeline relocations for the project.
The site is now prepared ready to start structural work on Bridge 11, a private access underpass. This will be a similar structure to the public underpass in Battle Hill Farm Forest Park.
Crane onsite ahead of the precast concrete beams being lifted into place for Bridge 6.
Bridge 11 foundation works underway.
State Highway 58 Interchange Bridge 13, Abutment B mechanically stabilised earth walls.
Construction of bridges for the new State Highway 58 Interchange is well underway. In early April, the road layout alongside our Lanes Flat site office will be changing, and the speed limit will be temporarily reduced to 30km/h to allow us to create a safe work area for our teams working on the State Highway 58 Interchange. Later this year, traffic will be shifted from the current alignment of State Highway 58 onto the new permanent road on the southern side of our site offices. We’ll keep you updated on works and what to expect leading up to the switch over.
Bulk earthworks remain the focus for the teams in this area, along with the construction of several bridges.
Earthworks underway in Belmont Regional Park looking north.
Belmont Regional Park access underpass (Bridge 18A) showing the completed base concrete pour.
Steady progress continues at the site of the Cannons Creek bridge, with four of the nine concrete pours for Pier 1 complete, and six of the nine permanent rock anchors installed. Teams are currently assembling and installing the reinforcing cages for Pier 2.
The first shipments of launching gear have arrived on site. Once assembled, the 60 metre long launching nose, weighing 240 tonnes, will connect to the girders and help guide the bridge across the valley. We successfully tested this technology recently using a large-scale version of the launching nose bearings.
In early April, the first of the bridge’s massive steel girders arrived on site from Napier.
Check out the video below for a bird’s eye view of the latest works underway for this impressive structure.
View of concrete pouring works underway for Pier 1.
Assembly and installation of the reinforcing cages for Pier 2.
View looking over the launch yard with launching nose assembly underway.
A scale version of the bridge’s launch bearings successfully tested.
From the top of Takapu Road, heading south, subgrade placement and foundation treatments continue, with the Transmission Gully motorway alignment now clearly visible through this area.
Looking south over earthworks underway behind Porirua Park in Cannons Creek.
Looking north over fill earthworks underway behind Ranui and Cannons Creek.
The concrete columns for Bridge 27 Abutment B are now complete. These are the columns that will form part of one of the two bridges for the Kenepuru connector road. Bridge 27 will span the existing SH1 while Bridge 28 will span the North Island Main Trunk (NIMT) railway line and Kenepuru Stream
Over the Easter break, concrete deck panels for Bridge 28 were lifted into place over the NIMT railway line, which is a quiet time for KiwiRail and allows power to be shut down.
You may have noticed a large hole in the ground beside Bridge 28, visible from Kenepuru Drive and passing trains. We’re currently removing liquefaction prone material, which will be replaced with suitable stable material for the foundations of the embankment for the approach to Kenepuru Drive. Once the foundations are complete, the MSE wall construction will begin to build the road level up from Kenepuru Drive to the new bridge.
Important information for motoristsWe’d like to remind motorists to take care when driving through this area along SH1 and to obey all temporary speed limits in place for everybody’s safety. For motorists travelling north, the speed limit is 70km/h and for southbound traffic the speed limit is 80km/h.
Construction works are well underway for a large MSE wall, which will form part of the approach for the northbound connection to the new motorway (Bridge 25). This wall runs alongside Arthur Carmen Park and the eastern end of Mexted Terrace.
The retaining walls (‘L walls’) for the approach embankments on the northern side of the Collins Avenue overbridge (Bridge 26) are complete and the southern side is nearing completion. The level of the motorway is being raised to the same height as the new section of bridge that is in place, and the retaining walls are part of this work.
South of the Collins Avenue bridge, construction of retaining walls, on the eastern side of State Highway 1 is nearly complete. Soil nailing and shotcrete works are complete and capping beam is being placed. These walls will have attractive precast concrete facing panels covering the shotcrete.
Bridge 28 foundation treatments underway with the removal of liquefaction prone material.
Construction works underway on a retaining wall beside Arthur Carman Park.
L wall construction underway for a new section of the Collins Avenue bridge (Bridge 26).
Retaining wall capping beams construction.
Transmission Gully motorway mural by Porirua graffiti artist, Anthony (Antz) June.
The Mobile Visitor Centre arrived in Tawa over Easter. Located next to the New World, why not take some time to drop in if you’re shopping or passing by.
Complete with a brightly coloured exterior mural, the visitor centre includes an interactive fly-through, maps of the new motorway and its interchanges, photos of construction progress, and a series of information panels about the project.
The visitor centre is open Monday to Friday between 8:30am and 4:30pm, and will remain on site until the end of May 2018.
Landscaping and mitigation planting for the project is now well underway. Around one million native trees and shrubs will be planted over the coming year. Many of these natives have been germinated, and are growing in nurseries around the region. The first of our quarterly landscaping inspections for the area took place in February, and we’re pleased to report that the natives planted at a Pauatahanui community planting day in September last year are thriving.
1L Pittosporum Tenuifolium, 500mm in height – September 2017.
Pittosporum Tenuifolium, 900mm in height – February 2018.
Sam Aitkenhead, CPB HEB JV Zone 2 Manager.
Listen to regular radio interviews with our team to hear more about what they're working on for the project.
In the latest radio interview, Sam Aitkenhead, CPB HEB JV Zone 2 Manager talks about the works underway for the State Highway 58 Interchange, and upcoming traffic changes for motorists.
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We hope you enjoy reading these updates, and we’d love to hear from you. If you have any questions, comments or story suggestions, you can email them to info@tg.co.nz.
