Millennium Line - Broadway Extension: Planning & Pre-Construction

[Gordon]

deeper excavations may be required anyhow because Broadway Has a fair amount of infrastructure under the roadway which would have to be moved for a cut and cover excavation so a bored tunnel might be less of a problem.

[logan5]

The stations will be excavated and they are only 850 meters apart so I don't think it will make much difference if you're doing cut and cover the short distance between stations. Even with a bored tunnel, the stations are still going to be extremely disruptive. If the savings are in the 100's of millions, then you easily have enough savings to compensate businesses. Like I said though, station construction will probably effect businesses just as badly as anything.

[officedweller]

Originally Posted by Gordon

deeper excavations may be required anyhow because Broadway Has a fair amount of infrastructure under the roadway which would have to be moved for a cut and cover excavation so a bored tunnel might be less of a problem.

I would expect tunnelling method to be corridor specific.

On 10th you could do either cut and cover or boring.
Under Broadway, because of the infrastructure, boring would be the cheaper option.

[WarrenC12]

Originally Posted by logan5

The stations will be excavated and they are only 850 meters apart so I don't think it will make much difference if you're doing cut and cover the short distance between stations. Even with a bored tunnel, the stations are still going to be extremely disruptive. If the savings are in the 100's of millions, then you easily have enough savings to compensate businesses. Like I said though, station construction will probably effect businesses just as badly as anything.

I'm not sure about that, doesn't the city effectively have lots set aside for stations? How big of a hole do you need? I remember downtown having some traffic redirection but nothing I'd describe as "extremely disruptive" for the 3 Canada Line stations.

[logan5]

I thought it was 8th ave that had utilities underneath.

[logan5]

Originally Posted by WarrenC12

I'm not sure about that, doesn't the city effectively have lots set aside for stations? How big of a hole do you need? I remember downtown having some traffic redirection but nothing I'd describe as "extremely disruptive" for the 3 Canada Line stations.

If I recall correctly, the whole block between Robson and Georgia was blocked off, except for a sidewalk. That's 160 meters for much smaller Canada Line stations. Bombardier stations would take up (I'm guessing) 200 meters at least, so you're left with around 650 meters of free space between stations.

[jsbertram]

I found this from the blog on the new Central Subway in San Francisco:


from: www.centralsubwayblog.com

I don't see many cars getting through there during the Cut & Cover construction.

[jsbertram]

Originally Posted by WarrenC12

I'm not sure about that, doesn't the city effectively have lots set aside for stations? How big of a hole do you need? I remember downtown having some traffic redirection but nothing I'd describe as "extremely disruptive" for the 3 Canada Line stations.

Davie not connecting to Pacific for several years was what I would call "extremely disruptive".

[jsbertram]

Originally Posted by logan5

The stations will be excavated and they are only 850 meters apart so I don't think it will make much difference if you're doing cut and cover the short distance between stations. Even with a bored tunnel, the stations are still going to be extremely disruptive. If the savings are in the 100's of millions, then you easily have enough savings to compensate businesses. Like I said though, station construction will probably effect businesses just as badly as anything.

Canada Line construction didn't have compensation for businesses affected by construction.

From the Sun:

Susan Heyes, owner of Hazel & Co., was awarded $600,000 in damages as compensation for the construction that disrupted her sales from 2005 to 2008. However, that judgment was overturned by the Court of Appeal in 2011.

http://www.vancouversun.com/news/Cambie+...+against+Canada+Line/10413867/story.html

Even though she won and then lost on appeal, over 200 Cambie merchants joined together for a Class Action lawsuit that is still working its way through the courts.

[Gordon]

Would the stops along Broadway not Mirror the current B Line stops
Cambie VGH Granville Arbutus MacDonald Alma Sassamat and on

most of theses stops are 7 or 8 blocks apart

[jsbertram]

Originally Posted by hollywoodnorth

that used to be common (leaving them in a stub tunnel to rust) not anymore.

that said NYC recently did that >> http://www.nytimes.com/2011/07/25/nyregion/deep-below-park-avenue-a-200-ton-drill-at-rest.html

where as in Toronto they sell the machines after use >> http://news.nationalpost.com/2014/05/07/...und-after-eglinton-lrt-line-is-finished/

Here's how San Francisco extracted their TBMs:

http://gizmodo.com/removing-a-tunneling-machine-from-the-ground-is-strange-1687180812

The NYTimes article is mixing up parts of the TBM used for digging the new East Side Access for the LIRR commuter trains to get to Grand Central. If you watch the gizmodo video, the first piece of the TBM to be removed is the rotating cutter head, followed by the 'circus train' of the TBM.

What the NYTimes article is doing is confusing the TBM cutter head with the rest of the TBM, leading to confusion about what was left behind under Park Ave south of Grand Central. Other sources are saying the TBM cutter head was detached from the rest of the TBM 'circus train', and the 'circus train' was partially backed away from the TBM cutter head. With room to work between the TBM cutter head and the 'circus train', the cutter head was encased in concrete to provide a solid end-cap to the tunnel. The rest of the TBM - the 'circus train' - was reversed back through the completed tunnel back to the launch-box pit where it was dismantled and extracted.

In Vancouver, the Canada Line construction was also done by a TBM, but in this case the 'launch box' was at 4th Ave @ Cambie, and the 'retrieval box' was at Granville @ Hastings. The single TBM built a tunnel under False Creek and Downtown from south to north, and at the Hastings pit the cutterhead was detached so the TBM could simply reverse backwards to the Cambie pit. While the TBM was being backed-up through the tunnel, the TBM cutter head was broken into parts and trucked back to the 4th Ave pit.

Once back in the launch box again, the TBM was repaired, the cutter head repaired, re-assembled and re-attached, and the TBM was shifted over to dig the second tunnel under False Creek and Downtown. When the second tunnel was completed, the TBM cutterhead was again removed and dismantled and trucked to the 4th Ave construction site while the rest of the TBM reversed back to the launch box where it was dismantled and extracted to be reused on a future project.

The launch box became the Canada Line Olympic Station and the retrieval box became the Waterfront Station between Pender and Cordova


geeky trivia:
Olympic Station has round tunnels on the north side and square tunnels on the south.

[jsbertram]

Originally Posted by Gordon

Would the stops along Broadway not Mirror the current B Line stops
Cambie VGH Granville Arbutus MacDonald Alma Sassamat and on

most of theses stops are 7 or 8 blocks apart

yup
8 blocks is roughly a mile.

[WarrenC12]

Originally Posted by jsbertram

The launch box became the Canada Line Olympic Station and the retrieval box became the Waterfront Station between Pender and Cordova

geeky trivia:
Olympic Station has round tunnels on the north side and square tunnels on the south.

So we know the square tunnel is C&C and round is bored.

Has anybody noticed that there is a very small segment between Granville and Stadium that is round? Was there some digging involved to connect the Stadium area to the old CP tunnel? Is that the round section? It's only 50-100 feet at most.

[officedweller]

Yes, the original entrance to the Dunsmuir tunnel veered south (over by Spectrum at Georgia St.). The Stadium Station portal was built for SkyTrain.
Doubt they would have bored it though because it's so short.

******

How soon everyone forgets...

Here's pic of the stacked tunnel excavation on Cambie Street - it's a pretty narrow trench.
You can see that it's within the roadway RoW, and there's at least 2 lanes of traffic maintained.
If it were trenched on 10th Ave., they could probably do with a single lane of traffic in most areas.


If they do cut & cover again, I'm sure they would require the contractor to provide a compensation package to area businesses.


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=14&by-date=false


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=13&by-date=false

You can see the stacked tunnels here:


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=10&by-date=false

http://canadalinephotos.blogspot.ca/

[SFUVancouver]

Originally Posted by jsbertram

yup
8 blocks is roughly a mile.

So one is no more than a four block walk from the closest station when they are spaced eight blocks apart. That's totally viable from the perspective of someone who walks and uses transit.

[Kisai]

Originally Posted by officedweller

Cut and cover along 10th would work easily if the tunnel is stacked.

The excavation down Cambie St. in the village area was quite narrow and could easily fit down 10th Ave.
Access to VGH Emergency could be maintained by excavating piecemeal and decking over the excavation.

A bored tunnel whether under Broadway or 10th will likely mean deeper stations, longer access times and multiple escalators switching back (like Yaletown-Roundhouse), which also means more repair and maintenance costs.

You wouldn't want to stack a tunnel if you didn't have to, as that increases the complexity and the required depth that the entire station has to reach (think Grandville station.) We only have the stacked tunnel because originally the Dunsmuir tunnel was meant for a steam locomotive, which coincidentally it's clearance requirements allowed for this. (If you've ever been on a double-deck Amtrak train, or even the WCE, you'd notice the height of the train is around 16'.)

You can see what the tunnel originally looked like:

Happy 80th Birthday to the CPR Dunsmuir Tunnel, Vancouver, BC by R R Horne, on Flickr

That said, cut-and-cover is a budget option for when you are digging up an existing ROW (eg the Arbutus corridor) not for digging up a major transportation corridor.

[officedweller]

Originally Posted by Kisai

You wouldn't want to stack a tunnel if you didn't have to, as that increases the complexity and the required depth that the entire station has to reach (think Grandville station.) [/URL].)

For a new build, think King Edward Station
- that's the only stacked station on the Canada Line.
They stacked the tracks through Cambie Village to keep the excavation narrow and maintain vehicle traffic.

It needn't be deep - so the platforms are easily accessible.

Here's King Edward Station under construction showing the 2 platform levels.


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=12&by-date=false

Earlier shot showing the station excavation and the stacked tunnel:


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=12&by-date=false


The main disadvantage would be access from only one side of the station.

The other disadvantage would be the construction of any crossover tracks, which would need a wider right of way area and be like the tracks around ST. George Station and Bay Station to transfer TTC trains between the Yonge-University-Spadina line and the Bloor-Danforth line.

Here's the excavation at Yaletown-Roundhouse (showing the tunnel liner before it was demolished)
- so it looks about one level deeper than King Edward Station:


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=14&by-date=false

Vancouver City Centre Station pit:


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=68&by-date=false


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=68&by-date=false

They excavated down to the first bore, then smashed the liner.
For the second tunnel bore, the TBM passed through the partially built station.


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=79&by-date=false


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=79&by-date=false

[jsbertram]

Originally Posted by officedweller

For a new build, think King Edward Station
- that's the only stacked station on the Canada Line.
They stacked the tracks through Cambie Village to keep the excavation narrow and maintain vehicle traffic.

It needn't be deep - so the platforms are easily accessible.

Here's King Edward Station under construction showing the 2 platform levels.

<snip>
Earlier shot showing the station excavation and the stacked tunnel:

<snip>


The main disadvantage would be access from only one side of the station.

The other disadvantage would be the construction of any crossover tracks, which would need a wider right of way area and be like the tracks around ST. George Station and Bay Station to transfer TTC trains between the Yonge-University-Spadina line and the Bloor-Danforth line.

Here's the excavation at Yaletown-Roundhouse (showing the tunnel liner before it was demolished)
- so it looks about one level deeper than King Edward Station:

<snip>

Vancouver City Centre Station pit:


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=68&by-date=false


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=68&by-date=false

They excavated down to the first bore, then smashed the liner.
For the second tunnel bore, the TBM passed through the partially built station.


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=79&by-date=false


http://canadalinephotos.blogspot.ca/sear...0Z&max-results=20&start=79&by-date=false

I loved the sidewalk along sears/eatons that was simply bolted to the side of the building.
Best spot for 'sidewalk supervisors' of any recent construction downtown.

[jsbertram]

Originally Posted by Gordon

deeper excavations may be required anyhow because Broadway Has a fair amount of infrastructure under the roadway which would have to be moved for a cut and cover excavation so a bored tunnel might be less of a problem.

The tunnels (and some stations) only need to be deep enough to let the TBM get under the existing infrastructure so it doesn't have to be moved. The Vancouver City Centre station construction photos show how deep the TBM tunnels were built, but it wasn't just the sewers, waterlines, telephone ducts, &tc in this area that had to be avoided, but the Canada Line had to get under the Pacific Centre food-court, then rise to get over the Dunsmuir Skytrain tunnel, and then drop down again to stay under Granville on the way to Pender.

[jsbertram]

Thought I'd share some photos of how Cut n cover is being done to build the new 2nd Avenue Subway in New York.

The Launch Box was constructed under 2nd Ave at 92nd St, but wasn't allowed block all the traffic since 2nd Ave is a major route on the east side of Manhattan and couldn't be blocked by an open pit for the better parts of a decade.


from http://thelaunchbox.blogspot.ca/2009/04/view-from-above-april-13-2009.html

Each of the 'tiles' is actually forming a concrete beam across the road acting as both the roadway and the roof of the launch box.

Digging under the road beams was done to make enough room for the TBM to be assembled. This launch box is actually 3 blocks long to hold the entire TBM before it starts building the tunnels.


from: http://thelaunchbox.blogspot.ca/2010/05/inside-launch-box-big-picture-may-14.html

The horizontal tubes (left to right in the photo) are structural to keep the launch box walls from buckling inwards. The floor of the launch box is roughly 100 feet below the street.

This TBM built the inbound tunnel from 92nd st to 63rd st, then was reversed back into this launch box, shifted over and then built the outbound tunnel, reversed again back to the launch box, and was dismantled and removed from the launch box.

Construction started in the fall of 2007, with the TBM starting its work in the spring of 2010 and finishing the tunnel borings in the fall of 2011.

The launch box is now being rebuilt as the northern terminus station for this phase of the 2nd Avenue Subway.

Opening date of this phase of the new subway extension is planned for December 2016.