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Mt Eden stormwater diversion works Updates

mt eden STORMWATER works - UPDATES

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On this page you will find a brief introduction to the stormwater work in the Mt Eden area followed by updates. The realignment works should be finished before the middle of the year.

THE WORKS

City Rail Link's C6 contract involves diverting a section of the existing Mt Eden stormwater pipe. It creates a new alignment between Water and Nikau Streets to enable CRL's redevelopment of the Mt Eden train station. The existing stormwater pipe was in the path of the new CRL tunnels that will be built there.

March Bessac Joint Venture (MBJV) was awarded the contract to undertake the works. MBJV is a partnership between NZ-based company March Construction and specialist French-based tunnelling company Bessac.

A micro-tunnel boring machine named Jeffie simultaneously tunnelled and laid a replacement 420-metre section of stormwater pipe. She was launched from a 16m-deep shaft at Water Street and arrived at her Nikau Street reception shaft in April.


THE NUMBERS

Water Street launch shaft: 16m deep secant pile construction, 8.5m internal diameter

Mt Eden Road access shaft: 18m deep, 2.5m internal diameter

Nikau Street reception shaft: 15m deep shaft, 9.4m internal diameter

Length of new stormwater line: 420 metres

Number of concrete pipe segments used: 215


In addition to the stormwater realignment, pollutant traps were installed at Boston and Normandy Roads as part of the stormwater network improvements for Auckland. They capture large and non-biodegradable waste such as litter and coarse sediment to prevent it reaching waterways.


THE MACHINE USED

Micro-tunnel boring machine

The tunneling was done by a German-built Herrenknecht AVN machine. You can read about how it works here.

The machine was named Jeffie following a hugely popular CRL social naming contest. The most popular name was Jeff but traditionally such machines adopt a female name so Jeffie - a popular girls name in the early 1900s - was chosen.

Naming digging equipment after women is said to be a tradition that dates to the 1500s when miners prayed to St. Barbara to keep them safe underground.

Saint Barbara is the patron saint of armourers, artillerymen, military engineers, miners and others who work with explosives because her legend associated her with lightning.

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PROJECT UPDATES

19 June 2019

Jeffie leaves

From solving a stormwater issue in Auckland to helping the water supply in Ecuador.

She has just finished replacing the stormwater main around Mt Eden’s Water and Nikau Streets as it was in the path of the future CRL tunnels.

Jeffie heads to port June 2019.jpg

She's shown heading to port for her sea voyage.

The micro tunnel boring machine is off to dig a 4km long tunnel in the second biggest city in Ecuador, Guayaquil. Guayaquil is on a river estuary and the tunnel will take water from the river to a new treatment station.

The machines are given female names as an acknowledgment of St Barbara, patron saint of miners and tunnellers, and Jeffie will be blessed with a new name in Ecuador.


Update

10 June 2019

The Mt Eden stormwater diversion work is in its final stages, with completion expected in early July. We greatly appreciate your patience during the construction period.

Nikau Street

The painstaking work of mining the connection tunnel from the Nikau St shaft to the existing stormwater pipeline is progressing well. A 24-hr operation commenced from Queen’s Birthday Weekend.

NIKAU: Mining for the pipe connection at Nikau Street

This is necessary because of the fragile nature of the excavation, requiring continuous support and monitoring. Work is being done underground however there will also be a fan above ground, audible to nearby residents. Please be assured we have reduced noise as much as possible to minimise disruption, and it is well below allowable noise limits.

We apologise for any disturbance while this work is undertaken.

We estimate it will take around two weeks – dependent on ground conditions. To create the connection we are installing the same type of pipe segments used in the main tunnel. However this time, excavation cannot be done by a tunneling machine.

This is because [it is unfeasible to use this machinery for the short connection into the existing pipe]. Therefore works must be undertaken by hand using hand held jack hammers, shovels and picks.

We estimate that there is just over a metre to be mined before the existing stormwater pipe is reached.

The last metre will be advanced with concrete pipes, after which we will dig out around the existing stormwater pipe. To keep the excavation stable while we dig around the existing pipe, rock bolts will be drilled into the walls and roof. This creates space for it to be enveloped with reinforced concrete before it is cut into.

Water Street

We are currently working on the permanent access chamber, which had been created off-site and will be lowered in.

An open trench method will be used to expose the existing stormwater line, after which we will build a connection between the old and the new lines.

WATER ST SITE: Preparation of permanent chamber to be lowered into shaft

Now that the tunnel is complete, Jeffie the tunnel boring machine, the bentonite slurry plant, the tunnel computer guide control container and all ancillary equipment have been removed from the Water St site.

28 Mt Eden Rd

GETTING READY: Preparation for breaking into the tunnel

The excavation of this shaft is complete. We are now preparing to cut into the top of the tunnel so that the access shaft to the tunnel can be connected.

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EXCAVATION: With the ventilation shaft

13 May 2019

28 Mt Eden Rd

The excavation of the Mt Eden shaft had to wait until the Jeffie and the tunnel were finished.

Now we are proceeding to excavate down to the tunnel, where we will cut a hole in the tunnel and build up an access chamber to the ground surface.

This shaft is the smallest of the three shafts on site and the excavation has progressed very quickly.


Water Street

CUT: The cut in the Water St shaft pile wall into the trench connection

The trench has been completed to full depth and the existing stormwater pipe is exposed, ready for the connection to the Water St shaft and the tunnel.

As we complete the removal of the equipment from the tunnel, work will start on the access chamber inside the shaft at the beginning of the tunnel and on the box connection from the shaft to the stormwater pipe.


Nikau Street

The Nikau St shaft is in transition.

The tunnel is now complete and we have successfully carried out the break out through the cassion walls to remove Jeffie.

Now we must make a much shorter tunnel, pushing the same type of pipe segments from the shaft to the existing stormwater pipeline at this end of the tunnel.

NIKAU: a Crane lowering equipment into the shaft for the mined connection

We are lowering all of the equipment needed to push four pipe segments across the eight or so metres to the stormwater pipeline. Work will continue underground for the next two months as we finalize the connection.

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24 April 2019

Jeffie finishes her job

Micro-sized tunnel boring machine, Jeffie, has completed her underground journey below Mt Eden.

She led the way digging out the tunnel for a new 423m long stormwater pipe 17 metres below city streets.

City Rail Link's C6 contract involves diverting a section of the existing Mt Eden stormwater pipe. It creates a new alignment between Water and Nikau Streets to enable CRL's redevelopment of the Mt Eden train station. The existing stormwater pipe is in the path of the new CRL tunnels that will be built there.

The existing stormwater main between Water and Nikau Streets was in the path of the future CRL tunnels and had to be diverted.

Jeffie began work in January with two jobs to do: excavating spoil and, at the same time, installing concrete segments for the new drain.

She removed more than 2,000 cubic metres of spoil, installed 208 concrete segments, and made a sweeping curve underground to avoid a field of hard volcanic basalt rock in her way.   During the journey, Jeffie encountered a part of Auckland’s distant past - the remains of a tree thought to have been destroyed in a volcanic eruption some 20 thousand years ago.

Now Jeffie is finished, she is off to Ecuador.

Work on the C6 project is now concentrated on making the underground connections between the existing stormwater pipeline laid behind Jeffie and to build the permanent concrete access chambers to and from the new pipeline from 15m underground up to the surface. There are three access chambers; in the launch shaft at Water St, the receiver shaft at Nikau St and an intermediate one about one third along at Mt Eden Rd.


01 February 2019

Jeffie milestone

Jeffie has completed the first 100 metres of her 420-metre pipe-jack journey.


11 January 2019

Jeffie starts her journey

Jeffie – the micro tunnel boring machine installing a replacement stormwater main through Mt Eden – started her 420m pipe-jack journey from Water St today.

Tunnelling at a depth of about 17m, Jeffie is expected to arrive at her Nikau St reception shaft in late March. The existing stormwater main lies in the path of the future CRL tunnels at Mt Eden, so must be diverted before work can begin on building the new station and twin underground tunnels in the area.

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19 December 2018

Jeffie lowered into the shaft

Today Jeffie, the tunnel boring machine being used at Mt Eden, was lowered into the launch shaft in Water Street and will start her pipejack journey towards Nikau Street in the new year.

Jeffie will be used to help divert a section of the existing Mt Eden stormwater pipe, which will be in the way of the CRL tunnel.


04 December 2018

Ceremony for tunnel boring machine

A blessing was held today for Jeffie, the tunnel boring machine being used at Mt Eden.

Jeffie is expected to be lowered into the launch shaft in Water Street by Christmas and start her pipejack journey towards Nikau Street in the new year.

St Barbara is the patron saint of miners and tunnellers. A statuette of her was carried by MBJV tunnel supervisor Laurent LeCalvez down the shaft at Mt Eden where tunnel boring machine Jeffie will be used to help divert a section of the existing Mt Eden stormwater pipe, which will be in the way of the CRL tunnel.

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WORKERS: The MBJV team

It’s traditional when a new project starts for a small shrine to Santa Barbara to be set up at the tunnel, followed by a dedication and an invocation to Santa Barbara for protection of the workers.

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19 November 2018

Water St shaft excavation reaches halfway

At Mt Eden, work is progressing on construction of 17-metre-deep shafts required as part of CRL’s stormwater realignment contract.

Contractor March Bessac is tasked with diverting a 420-metre section of stormwater main that lies in the path of the future CRL tunnels at Mt Eden.

The new main will be installed by a micro tunnel boring machine named ‘Jeffie’, who is expected to be lowered into the Water Street launch shaft in December and start her journey towards the Nikau Street reception shaft in the New Year.

The concrete pipe segments that will be pushed along behind Jeffie as she bores the new stormwater tunnel continue to arrive at the Water Street construction site.

A bentonite plant has also been established to assist with the pipe-jack work. Bentonite is a special type of clay used in tunnelling to create a fluid sleeve around the pipeline to help keep the soil from closing in during works.

A bentonite slurry circuit is also used to carry the tunnel cuttings to the surface for separation. The treatment plant separates the solids from the bentonite fluid and returns it to the tunnelling machine. The solid material generated will be carted to a certified fill site.

A special ceremony for Jeffie will be held on 4 December, St Barbara’s Day. St Barbara is the patron saint of miners, making it an appropriate day to hold a ceremony to bless the workers and equipment before the tunnelling work begins.


10 September 2018

Ground support begins - Mt Eden, Water St 10 Sept 2018

Ground support begins

Ground support work has begun at CRL’s Ruru St site in Eden Terrace. Posts are being installed before construction of a 15m-deep shaft that will receive the mini tunnel-boring machine (TBM) that will lay a replacement stormwater pipe from Water St.

The existing stormwater main lies in the path of the future CRL tunnels at Mt Eden, so must be diverted before CRL’s station and tunnel works can begin in the area.

Contractor March Bessac JV is also completing piling works at the Water Street site in preparation for the 17m-deep shaft that will launch the TBM on her 400-metre journey.

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27 July 2018

Jeffie arrives on site at Mt Eden

‘Jeffie’, the mini tunnel boring machine that will pipe-jack a replacement stormwater line at Mt Eden ahead of CRL tunnelling works, has arrived on site at Mt Eden Road.

A German-built Herrenknecht AVN machine, Jeffie was sent to New Zealand from her base in Toulouse, France. She’s expected to start work in October - simultaneously excavating and laying a replacement 400-metre section of stormwater pipe between Water Street and the Ruru Street. The existing stormwater main lies in the way of the future CRL tunnels at Mt Eden.


13 July 2018

Installation of the first 18m-deep pile at Water St

Piling works begin at Water Street

Piling works have begun at the end of Water Street ahead of CRL’s Mt Eden stormwater realignment works.

Contractor March Bessac Joint Venture (MBJV) is installing 89 piles to support the ground before it starts construction of the 17-metre-deep shaft that will launch Jeffie on her pipe-jacking mission. Work on the Water Street shaft is expected to begin late August, with all piling works completed in early September.

In addition to the stormwater realignment, pollutant traps are being installed at Boston and Normandy Roads as part of the stormwater network improvements for Auckland. They will capture large and non-biodegradable waste such as litter and coarse sediment to prevent it reaching waterways.

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02 July 2018

Shaft guide walls go in at Water Street site

SITE WORKS: Preparing for the construction of shaft guide walls

At CRL’s Water Street site, construction is about to begin on the 17-metre-deep shaft required to launch the micro tunnel-boring machine (MTBM) that will install the new Mt Eden stormwater line.

The existing stormwater main sits lies in the way of the future CRL tunnels at Mt Eden, so a 400-metre section of the main must be diverted before the project’s main station and tunnels work can begin in the area.

A piling rig will start installing the shaft walls this month. Contractor March Bessac Joint Venture (MBJV) has selected equipment that minimises noise and vibration as much as possible, in this case a rig that bores the piles with a large auger rather than hammering steel piles into the ground.

‘Jeffie’, the MTBM that will pipejack the replacement stormwater main, is making her way to Auckland from France. She is due to arrive in mid-July and start pipejacking in October.

A second shaft will be created on the corner of Ruru and Nikau Streets, where Jeffie will complete her journey and be lifted out of the ground.


22 May 2018

Second demolition completed

We're almost ready to start diverting a section of the existing Mt Eden stormwater pipe.

This is all that remains of the former Hyde Group building at Ruru St.

This needed to go before we start on the stormwater pipe.


17 May 2018

Boring machine on its way

The new micro tunnel boring machine (MTBM) named Jeffie is now on its way from France.

She'll be working on the Mt Eden stormwater realignment.

Jeffie will be launched from Water Street and travel underground to Ruru St to divert the stormwater line which is currently in the way of where the tunnels will be.


14 May 2018

Demolition finished

They're gone! The apartment building at 26 Mt Eden Road has now been demolished.


04 May 2018

Demolition going well

Here are the latest pictures showing the status of the demolition of the apartments at 26 Mt Eden Road.

 
 

30 April 2018

Demolition update

The demolition at 26 Mt Eden Road is continuing.


DEMOLITION: Demolition of the apartments at 26 Mt Eden Rd underway

23 April 2018

Demolition works

Before the stormwater diversion, CRL needs to demolish apartments at 26 Mt Eden Road and the former Hyde Group building on the corner of Nikau and Ruru Streets. The demolition began today at 26 Mt Eden Road.

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FOR INFO ABOUT THE REDEVELOPMENT —