afransen
Senior Member
The largest TBM in the world is only 18m. If you were to stack two levels of roadway in such a tunnel, the effective ROW width would be narrower.
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Highway 401 Transit and Auto Tunnel
- Thread starter UrbanAffair
- Start date
afransen
Senior Member
It makes zero sense to build a tunnel and run a BRT in it.
nfitz
Superstar
All very interesting - at least from a hypothetical engineering view.The Globe's latest take on this:
Ford proposes three-level tunnel under Highway 401, feasibility study not started
His plan is to have a 19.5-metre-wide, three-level tunnel, with one level going eastbound, one for westbound traffic and a bottom level for transitwww.theglobeandmail.com
The only detail of note is limited info as to width and depth:
View attachment 671692
Looking at the existing 401 in Toronto, the MTO designs to a 3.5M wide lane of traffic. and 3M paved shoulders
My read of a 19.5M would be 4 lanes per direction plus shoulders.
The minimum vertical clearance on the 401 is 5M (pavement surface to below the girder of an overpass)
Metrolinx requires 7M above top-of-rail. Rail base is likely in the range of 0.4M plus the rail height for about 0.5M
Allowing some margin of error, excluding slabs, below, between and above, you get a required depth in the range of 18M
I'm not sure how thick the slab between levels would be, but general recommendations suggest 400mm for bored tunnel and 900mm for cut and cover.
Looking at the North Connex project in Australia, tunnel depth ranges from 60M to 90M while West Connex is in the 35M to 40M range.
However, these seem to be single-level.
Three distinct levels would require substantial depth.
Given the width of the highway here, the choice to go only 19.5M wide and much deeper is suggestive of a cut and cover construction and trying to limit how much highway you close at any one time.
The river crossing issues here would be substantial.
And where, I ask, are the bike lanes going to be in that tunnel structure?
innsertnamehere
Superstar
The way I read it, it would be a 19.5m bored tunnel. They are pretty explicit that it would be bored.The Globe's latest take on this:
Ford proposes three-level tunnel under Highway 401, feasibility study not started
His plan is to have a 19.5-metre-wide, three-level tunnel, with one level going eastbound, one for westbound traffic and a bottom level for transit
The only detail of note is limited info as to width and depth:
View attachment 671692
Looking at the existing 401 in Toronto, the MTO designs to a 3.5M wide lane of traffic. and 3M paved shoulders
My read of a 19.5M would be 4 lanes per direction plus shoulders.
The minimum vertical clearance on the 401 is 5M (pavement surface to below the girder of an overpass)
Metrolinx requires 7M above top-of-rail. Rail base is likely in the range of 0.4M plus the rail height for about 0.5M
Allowing some margin of error, excluding slabs, below, between and above, you get a required depth in the range of 18M
I'm not sure how thick the slab between levels would be, but general recommendations suggest 400mm for bored tunnel and 900mm for cut and cover.
Looking at the North Connex project in Australia, tunnel depth ranges from 60M to 90M while West Connex is in the 35M to 40M range.
However, these seem to be single-level.
Three distinct levels would require substantial depth.
Given the width of the highway here, the choice to go only 19.5M wide and much deeper is suggestive of a cut and cover construction and trying to limit how much highway you close at any one time.
The river crossing issues here would be substantial.
MTO freeway lane width is typically 3.75m, 3.5m is usually reserved for "substandard" sections which are width constrained or construction zones.
I interpret it to be 3 lanes in each direction, 3 and 1.5 metre shoulders, plus a lower transit deck. The lower transit deck would likely not meet full mainline rail standards and be designed only for a specific train type, which likely won't be Bombardier bi-levels.
If MTO is willing to do more substandard lane and shoulder standards, it could be 4 lanes each way pretty easily, but I suspect they will go with 3 lanes for safety reasons.
With a bored tunnel, you launch the mega-TBM on one end, and let it dig as deep as you need to get to the other end to go under river crossings, etc.
I suspect "phase 1" would be a tunnel from the 427 to somewhere east of the 404, with interchanges at the 404 and 400 and that's it. Interchanges would be cut and cover most likely in the area of each freeway interchange, then the TBM can go as deep as it needs in between to get around obstacles. Limited construction surface impacts beyond the interchange locations.
A 6-lane highway with an 80km/h limit and limited to no interchanges would offer a surprisingly huge vehicle capacity - likely supporting around 150,000 AADT. That would be a fairly substantial addition to east-west capacity. If they squeezed in 8-lanes, you could probably push 200-250,000 daily vehicles through it. The super express nature of it would also make it not really serve local commuting patterns, instead functioning more as a regional connector for traffic trying to go across the GTA, not to it. Of course with that traffic moved off the existing 401, it would leave more capacity on the existing 401 for those commuters..
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micheal_can
Senior Member
My riding isn't blue. So,we did not vote him in. Those in blue ridings, especially those in blue ridings that vote blue voted him in.
How many lanes would realistically fit in a tunnel that used it? I know not all 18m can be roadway.
BrenWilson
Active Member
If only we had a space for a regional express route through the GTA without resorting to a tunnel! You could toll it even, and call it an Express Toll Route.
Mihairokov
Senior Member
We, the people of Toronto, have not given him three majorities, despite his biggest want seeming to be Mayor of Toronto.
Toronto should be its own special administrative district separate from Ontario. It shouldn't be possible for a Premier voted in by rural and suburban voters to circumvent everything in the city on a whim. The city is too large for the rest of the province politically.
lenaitch
Senior Member
Fair. Not much talk about selling Wasaga Beach to the highest/friendliest bidder.
It is somewhat similar to him saying he is "all in" on twinning northern highways. Being 'all in' doesn't cost him a dime.
I'm not smart enough to be able to math our what the vertical clearances would be for the upper and lower levels as you move away from the centreline.
I maintain you would definitely need at least one full lane-width shoulder for refuge.
Bring your own Scott Air Pack?
Northern Light
Superstar
Ok.....I'm not going to get into the weeds on all the speculation...........but I will point out that with a very maxxed out 6% grade............to come from a depth at least 35M below the West Don River to the exiting 401 elevation would entail a 1.2km long ramp.
Just sayin.
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micheal_can
Senior Member
Without going into the weeds, dicing up the province into smaller, more like minded provinces would solve a lot of more local/regional issues. This is one topic I could go on for pages and pages.....
The thing is, the city of Toronto, should be part of the GTAor the Golden Horseshoe or GTHA 'province' anyways. And....Ford is from Toronto.
txlseries4
Active Member
Ummm actually he's from The Great State of Etobicoke, thank you very much
micheal_can
Senior Member
Which since The Common Sense Revolution has been a part of the City of Toronto.
txlseries4
Active Member
It was a joke. He often says he's from "the great state of Etobicoke"
innsertnamehere
Superstar
something like this..
micheal_can
Senior Member
One of the many things he says that still annoys me.
Any of my friends that have cottages have invited me to them.Still waiting for his invite since he thinks I am his friend.
If it wasn't for the 18 lane highway above it, this wouldn't be horrible. But that is just it, in theory, this isn't a horrible plan on its own. What is horrible is when we put some reality in it.