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drum118 said:
From photos I have seen, the road was open until there was room under the timber beam for equipment to dig the earth. Once that was done, then traffic and streetcar ran on top of it until it had to be back fill for the new road and sidewalks to be built.
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Thanks,
The impression is given that Yonge was an open pit for 5 years.

I am still convinced that with precast concrete and high-early (HE) strength concrete (formerly Type 30), they could cut, lay down tunnel, and cover within a month. At the stations, they would have to do decking (similar to the photo above), but the excavation would be half the depth (or less) of the tunneled station and its construction would be done in less time than the current method. (Eglinton may be an exception, because if the road has steep grades, the cuts may become excessively deep).
 
Is there any kind of explainer on how the transit signaling priority in the grade portion of the LRT is going to be figured out?
 
BurlOak said:
Thanks,
The impression is given that Yonge was an open pit for 5 years.

I am still convinced that with precast concrete and high-early (HE) strength concrete (formerly Type 30), they could cut, lay down tunnel, and cover within a month. At the stations, they would have to do decking (similar to the photo above), but the excavation would be half the depth (or less) of the tunneled station and its construction would be done in less time than the current method. (Eglinton may be an exception, because if the road has steep grades, the cuts may become excessively deep).
Click to expand...

That's basically what they did on Yonge at the time - replacing timbers for the concrete slabs - and what they have been doing at sites such as Sheppard-Yonge and Finch West stations more recently. And what they will be doing at most of the station sites on the Crosstown as well.

The problem is that you still need to have some access to the surface - the trucks need to be able to get in and out of the site somehow - so no matter what, there will be some reduction in lane capacity at the site for a long period of time.

Dan
Toronto, Ont.
 
BurlOak said:
I am still convinced that with precast concrete and high-early (HE) strength concrete (formerly Type 30), they could cut, lay down tunnel, and cover within a month. At the stations, they would have to do decking (similar to the photo above), but the excavation would be half the depth (or less) of the tunneled station and its construction would be done in less time than the current method. (Eglinton may be an exception, because if the road has steep grades, the cuts may become excessively deep).
Click to expand...

A great idea for tunneling. You only cut half way down, deep enough to take the overhead off the TBM, so nothing collapses. Then you let the TBM run along, waist deep, boring out the bottom half. That way, your temporary retaining walls are only half as deep as traditional cut and cover. Probably, with the top of the TBM exposed, the tailings could be fed directly out the top instead of back down the tunnel. You run a conveyor back to where you need to cover, and dump the tailings there. It covers itself as it moves. You build out of prefab shell, just like a true TBM does.....no forms needed.

Of course, with the stations being voids, you still have to do them the same way, but the impact along the route is much less, and doesnt last long. You can do the tunnels. much closer to the surface, making stations cheaper.

- Paul
 
BurlOak said:
I am still convinced that with precast concrete and high-early (HE) strength concrete (formerly Type 30), they could cut, lay down tunnel, and cover within a month.
Click to expand...

Remember, this work was done in the early 1950s. Concrete technology was much less advanced than now. I don't have precise timelines, but the timbers across the I-beams became the road surface while work went on below, section by section, not the entire length of the project. And that involved an incredible amount of work relocating (and rebuilding) infrastructure. So nothing was done in a mere month.
 
crs1026 said:
A great idea for tunneling. You only cut half way down, deep enough to take the overhead off the TBM, so nothing collapses. Then you let the TBM run along, waist deep, boring out the bottom half. That way, your temporary retaining walls are only half as deep as traditional cut and cover. Probably, with the top of the TBM exposed, the tailings could be fed directly out the top instead of back down the tunnel. You run a conveyor back to where you need to cover, and dump the tailings there. It covers itself as it moves. You build out of prefab shell, just like a true TBM does.....no forms needed.

Of course, with the stations being voids, you still have to do them the same way, but the impact along the route is much less, and doesnt last long. You can do the tunnels. much closer to the surface, making stations cheaper.

- Paul
Click to expand...

One note on why this is difficult - the TBM pushes on the existing tunnel segments to move forward. I had trouble finding a good image, but if you look in the one below of the Eglinton TBMs below, if you look at the inside of the machine, you can see the 'thrust pads' as they're called. They are what push against the tunnel segments to advance the machine. Having done the layout myself on these machines, you can see we made those pads as large a contact area as could fit, because you need to distribute the thrust with as little contact pressure as possible. Too high a contact pressure, and you risk cracking the segments, or you have to greatly increase the compressive strength of the concrete used in the segments. The thrust of the machine has to be enough to both push the machine through what its mining, and overcome the friction of dragging the trailing gantries full of equipment.

Now if you expose half the TBM, you might lessen the force needed to mine forward, but not the force required to drag the machine. Loosing half the tunnel to push off means you're doubling the contact pressure on the concrete segments. Its probably not insurmountable, but would need special tunnel segments and concrete for the station areas.
3-Crosstown-Caterpillar-TBM1.jpg


The real reason they split the tunneling contracts off for Eglinton from stations was that they wanted to advance the TBM procurement as quickly as possible...if they'd left the tunnels to the consortiums building the stations in the DBFM contract, the consortium would've had to the wait the 18 months to construct the TBMs they individually ordered (after they won), which would've pushed back the whole timeline.

My current place of work helped do the assessment that showed advancing TBM procurement (on a sewer project probably 10 years ago, which was then copied for TYSSE and Crosstown) would speed up the project timelines. That led to my old place of work building a lot of TBMs in parallel to the construction procurement processes, so when construction procurement was done, they had the machines ready to go.

Whether or not they follow the same model on SSE, DRL or YSE, I have no idea.
 
jcam said:
The real reason they split the tunneling contracts off for Eglinton from stations was that they wanted to advance the TBM procurement as quickly as possible...if they'd left the tunnels to the consortiums building the stations in the DBFM contract, the consortium would've had to the wait the 18 months to construct the TBMs they individually ordered (after they won), which would've pushed back the whole timeline.

My current place of work helped do the assessment that showed advancing TBM procurement (on a sewer project probably 10 years ago, which was then copied for TYSSE and Crosstown) would speed up the project timelines. That led to my old place of work building a lot of TBMs in parallel to the construction procurement processes, so when construction procurement was done, they had the machines ready to go.

Whether or not they follow the same model on SSE, DRL or YSE, I have no idea.
Click to expand...

This is key to getting the subway projects completed in a reasonable amount of time...all three subways that are being proposed should focus on getting the TBM's ordered - it's even more important than the funding of the entire project.

Toronto (and Tory specifically) should be focusing on ordering the TBM's using our own funding and plan to do most of the tunnelling ourselves and leave the stations and infrastructure to the province and feds.

Unfortunately we only have funding in place for Scarborough - and it's for the entire thing - so we are probably going to design all of it before ordering the TBM's for Scarborough...

That said council should focus on getting the TBM's for DRL purchased before the end of this term of council - for delivery mid-term of next and beginning of tunnelling by the end of next term. If they wait until there is a full contract in place we will not order them before 2022 or so...
 
georgevicbell said:
This is key to getting the subway projects completed in a reasonable amount of time...all three subways that are being proposed should focus on getting the TBM's ordered - it's even more important than the funding of the entire project.

Toronto (and Tory specifically) should be focusing on ordering the TBM's using our own funding and plan to do most of the tunnelling ourselves and leave the stations and infrastructure to the province and feds.

Unfortunately we only have funding in place for Scarborough - and it's for the entire thing - so we are probably going to design all of it before ordering the TBM's for Scarborough...

That said council should focus on getting the TBM's for DRL purchased before the end of this term of council - for delivery mid-term of next and beginning of tunnelling by the end of next term. If they wait until there is a full contract in place we will not order them before 2022 or so...
Click to expand...
I thought Vancouver, for both Canada Line and Evergreen Line, had the consortium do the TBM tunneling.
 
City of Toronto Eglinton East LRT Communications and Consultation Strategy 9120-17-7194

The purpose of this Request for Proposal (RFP) is to select a qualified communications, and public and stakeholder consultation consultant to work collaboratively with the City on public and stakeholder communications and consultation for the ongoing work related to the Eglinton East LRT Work Program.

The intent of this work is to provide strategic advice and support for all public and stakeholder consultation, facilitation, communications, and engagement for current and emerging projects associated with the Eglinton East LRT, and if required, prepare documentation that would inform a TPAP Amendment or other future work. The Program of LRT related projects that to be supported by this Project is expected to begin in Q3 2017 be completed by mid-2018.

The scope of this Strategy includes, but is not limited to:

- Communications strategy and project branding;
- Community consultation and implementation plan;
- Public and community consultations and stakeholder meetings (e.g. business community, community associations, university / college student population etc.);
- Workshops and/or charrettes;
- Communications materials and content preparation; and
- Social media and website presence.

A total fee (excluding HST) in the range of $300,000 - $350,000 has been estimated for this work. Please note that this amount is only an approximation and does not reflect the total amount that will be paid to any selected consultant. This amount is for information only and should not form the basis of any submission.
 

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EastYorkTTCFan said:
Interesting it seems a bit early for it I would have thought at last 2020 fro them to begin unless they want to speed things up because they realise it's taking way too long.
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No, it was always planned for prep work. Utilities relocation will begin sometime soon (if it hasn't happened yet). That would take them up to a year. They'll widen the roadway in 3 phases, medium, north and south side (don't remember which is first). That's 2-3 months per phase.

If they started prep work in 2020, it won't finish within a year. The actually track and overhead work won't happen till closer to 2020. Even the VIVA rapidways took much longer than a year.
 
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