Kia ora and welcome to the January 2018 update from the Transmission Gully team.
A section of the new motorway taking shape behind Whitby, with works now visible for the two new link roads.
Happy New Year – welcome to the first construction update for 2018.
Christmas and New Year is often a quiet time for construction projects, but there was no rest for the team with several crews working through the holiday period.
With the dry summer weather, bulk earthworks have been progressing well across the entire alignment, and if the good weather continues, we’ll be on track to beat our summer earthworks target of 4 million cubic metres of earth moved.
Here’s an update from the project team on what’s been happening over the last month, and what to expect over the rest of the summer season.
Cranes key to creating new connections
In the southern end of the project, the teams’ focus over Christmas and New Year was around Kenepuru and Linden. A key reason for this was to align our works with the quieter period to minimise any additional disruption particularly to rail travellers.
An important project milestone was achieved, with the successful installation of a section of steel bridge girders over the North Island Main Trunk railway line for the new Kenepuru connector road. Once complete, this new road will provide access for local residents on and off the new Transmission Gully motorway.
For the section crossing over the railway lines, two steel bridge girders were preassembled into a single span weighing 150 tonnes, and then lifted into position using a 600 tonne crawler crane. This is one of the largest crawler cranes in New Zealand and uses ‘super lift’ technology where a second boom lifts counterweights off the ground to balance the heavy preassembled girders.
The girders spanning over Porirua Stream were lifted using a 280 tonne crawler crane, which lifted the girders into place one at a time. The final girder was lifted and spliced into place on 3 January 2018.
You can now see the new section of bridge crossing over the railway line from Kenepuru Drive and check out the video below of the lift operation.
Visit our image gallery to see images captured on the day.
We’ve also made significant progress on the Collins Avenue bridge, with deck concrete pours for the first section of new bridge completed in late December 2017 and the mechanically stabilised earth retaining walls on the eastern side of the bridge completed in mid-January 2018.
The completed concrete deck for the first section of the new Collins Avenue bridge.
With the completion of this section of work, the team will now begin construction of 90 metres of concrete retaining walls for the bridge approach embankments.
As part of the work on the bridge, drainage upgrade works will take place on Collins Avenue. Some traffic management will be needed for this work, with a lane closure during the day. We’ll let residents know more information about these works closer to the start time.
Shotcrete application works are underway for the retaining walls south of Collins Avenue.
South of the Collins Avenue bridge, work is continuing on the retaining walls using soil nails and shotcrete. The walls will eventually have an urban-designed precast concrete facing panel covering the shotcrete.
We’ve started works on a large retaining wall for the northbound flyover - where the Transmission Gully motorway diverges from the existing State Highway 1, north of Linden School. Construction works will be visible from Arthur Carman Park and will be ongoing until August 2018.
Concrete pouring underway for the bridge pier foundations.
Concrete pouring for the bridge pier foundations is progressing well, with steel reinforcing being installed between each concrete pour. The first two shipments of launching gear for the bridge’s girders is on its way and the fabrication of the huge structural steel girders is ongoing.
In case you missed it last month, check out the animated video of how the bridge will be constructed and launched over the gully.
View looking north west over works underway in Belmont Regional Park.
Construction has started on the underpass that will provide access under the motorway for regional park users, as well as a bridge over Duck Creek for road users. Bulk earthworks remain a focus for the team working in this area over summer.
Work is well underway on the bridges that make up the State Highway 58 Interchange, as well as ongoing bulk earthworks through this area. We’ve also started work on a section of what will become the new road layout for State Highway 58, which is now visible beside our Lanes Flat site office in Pauatahanui. To complete the interchange, towards the end of this year, we’ll be switching traffic from the existing State Highway 58 road onto this new section of road.
View over works at Lanes Flat, Pauatahanui, including mechanically stabilised earth walls for the State Highway 58 Interchange.
Our teams are focusing on bulk earthworks at Battle Hill and some sections near Battle Hill Farm Forest Park are now at subgrade level, which is the final level of earthworks before construction of the road surface starts.
We’ve recently made live another 700-metre section of the permanent diversion of the Horokiri Stream. Construction works are moving ahead on the permanent channel for Te Puka Stream with one kilometre already complete and ready for water to flow through it in the coming weeks.
A section of the new motorway near Battle Hill Farm Forest Park, which is now built up to the final level before construction of the road surface begins.
View over the Horokiri Stream permanent diversion works. Works continue on a bridge that will cross over this section of stream.
View over works looking north from Battle Hill Farm Forest Park to the Wainui Saddle.
In the northern part of the project, our teams swung back into full production in early January. We’ve now completed all the preparatory earthworks for the motorway and local road and are in the final stages of shifting services such as gas, power and telecommunications. We’ll soon start work on new drainage and constructing the initial layers of the road surface.
View looking north over a section of the new motorway and local road at Paekakariki.
Important information for motoristsA new road layout is in place north of our Paekakariki site entrance on State Highway 1. The road is being narrowed south of the Mackays off-ramp to give room for construction beside the state highway. To allow for this work, the 80km/h speed limit has been extended from Paekakariki through to Mackays Crossing.
This road layout will be in place until the end of 2018, when State Highway 1 is temporarily switched onto the new coast road. Diverting traffic onto the local road will allow us to complete the new section of motorway where it crosses the current state highway with minimal disruption to traffic.
If you’re travelling in the area, please take extra care and adhere all traffic signs. We thank you for your patience.
As part of these changes, we’ll be creating a wider shoulder for cyclists along State Highway 1. However, we encourage people on bikes travelling between Paekakariki and Raumati to use Te Ara O Whareroa pathway through Queen Elizabeth Park to avoid the construction area altogether.
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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.
