Hwy 99 Fraser River Tunnel (George Massey Replacement) | Proposed

[officedweller]

Article regarding possible relocation of Massey Tunnel hydro lines to become overhead lines:

http://vancouversun.com/news/local-news/...s-could-soon-rise-above-deas-island-park

[Stingray2004]

Those 5 piles at the south end of the GMT? Test piles driven ~200 feet into the ground to collect geo-technical data for the engineering/design phase of the project:

• Video Link

[Metro-One]

How deep it is until bedrock there?

[Stingray2004]

Originally Posted by Metro-One

How deep it is until bedrock there?

The Fraser River bed, in that locale, is a 600 m (1,969 ft) thick layer of sediment on top of bedrock.

And the new GMB, with deep-piled foundations, will make the GMB safe for a 1 in 2,475 year earthquake.

However, for whatever reason, the pilings will not go down to bedrock. Apparently, that's not required. But complex structural engineering/seismic is not my forte, and frankly, over my head. Perhaps, someone on here, knowledgeable in that field, may be able to shed some more light on same.

I have previously sniffed around on the same topic vis-a-vis the new PMB and IBT Engineers has this tidbit suggesting that the piles thereto did not go down to bedrock either:

Foundations for the new Port Mann Bridge are generally 1.8-m (5.9-ft) steel piles or drilled shafts, supported on a firm ground till layer under the loose sand deposits at a depth below the river.

[emphasis added]

http://www.ibtengineers.com/PROJECTS/PortMann/portmann-1.html

[Marshal]

The main thing to note is that friction piles can provide all the structural support needed (for anything) so long as they are properly placed. The important variables are 1) the design of the piles themselves, 2) the composition of the soils they are placed in, and 3) the length of the pile that is engaging (generating friction as a resisting force). In this case, 600m is a very long way to reach bedrock, so there is probably plenty of resistance in the sediments above that can be utilized without any need to go that deep.

[Metro-One]

Interesting stuff. Amazing how deep the bedrock is there.

[Klazu]

Just a random tunnel photo.

[Kisai]

Originally Posted by Marshal

The main thing to note is that friction piles can provide all the structural support needed (for anything) so long as they are properly placed. The important variables are 1) the design of the piles themselves, 2) the composition of the soils they are placed in, and 3) the length of the pile that is engaging (generating friction as a resisting force). In this case, 600m is a very long way to reach bedrock, so there is probably plenty of resistance in the sediments above that can be utilized without any need to go that deep.

It may not be required, but that assumes that the sediment doesn't move, or won't be dredged and weaken it at some point.

AFAIK (I'm not a bridge engineer either) only two piles would need to hit bedrock (eg at the center span Pylon) to "anchor" the bridge from flowing downstream, sinking or rotating, the rest are only providing support to the other Pylons as the road deck is anchored to them as the pylon's force is straight down.

Ever try to pull a hose or fence post out of the ground? It's nearly impossible if it was driven into sand. But there is a natural ground creep that happens from underground water.

600m piles might not be doable simply because past a certain point the piles don't add any more support that wider piles wouldn't offer.

[Marshal]

Originally Posted by Kisai

It may not be required, but that assumes that the sediment doesn't move, or won't be dredged and weaken it at some point.

AFAIK (I'm not a bridge engineer either) only two piles would need to hit bedrock (eg at the center span Pylon) to "anchor" the bridge from flowing downstream, sinking or rotating, the rest are only providing support to the other Pylons as the road deck is anchored to them as the pylon's force is straight down.

Ever try to pull a hose or fence post out of the ground? It's nearly impossible if it was driven into sand. But there is a natural ground creep that happens from underground water.

600m piles might not be doable simply because past a certain point the piles don't add any more support that wider piles wouldn't offer.

Sorry because I don't have the time right now, but piles and the scale of the geology simply don't work in any way like you talking. I'll try to remember and explain tomorrow.

[officedweller]

June 24, 2016: The Ministry of Transportation and Infrastructure has submitted its application to the Agricultural Land Commission (ALC).
To review the application in its entirety please click on the following link:
ALC Application Sections 1-3 https://engage.gov.bc.ca/masseytunnel/files/2016/06/ALC-Application-Sections-1-3.pdf
ALC Application Sections 4-6 https://engage.gov.bc.ca/masseytunnel/files/2016/06/ALC-Application-Sections-4-6.pdf
ALC Application Sections 7-10 https://engage.gov.bc.ca/masseytunnel/files/2016/06/ALC-Application-Sections-7-10.pdf

http://engage.gov.bc.ca/masseytunnel/whatsnew/

[officedweller]

These maps show the lands to be acquired for the right-of-way - shown in blue.
The pink lands are existng right-of-way lands used for agriculture.

All from this report:
https://engage.gov.bc.ca/masseytunnel/files/2016/06/ALC-Application-Sections-1-3.pdf

[officedweller]

Now for the interesting stuff.

Here are close ups of the Steveston Hwy interchange, south end of the bridge and Hwy 17A interchange showing the bus stations and pedestrian and bike access ramps.

I'm not sure what the yellow line is - looks like bus station access (?).

All from:
https://engage.gov.bc.ca/masseytunnel/files/2016/06/ALC-Application-Sections-1-3.pdf


Steveston Hwy Interchange
(note ped/ bike paths on both sides of the bridge):
I just realized that the basketweave ramps allow a bus stop at the yellow box (elevator?) on the road above the median bus station -
and the bus door will be on the proper curb side.



Ped/Bike ramps to River Road
(note ped/bike paths on both sides of the bridge):



Hwy 17A Interchange:
Bus station access looks to be on the outside curbs for this conventional overpass.

[cleowin]

The Steveston Highway Interchange looks like one of those American Basketweave interchanges, pretty impressive!

[Klazu]

Originally Posted by cleowin

The Steveston Highway Interchange looks like one of those American Basketweave interchanges, pretty impressive!

Unfortunately it's only going to be a 3-level stack.

How do I read those diagrams? Is there going to be a ramp down to River Road or not?

[excel]

Pretty impressive interchanges.

[Metro-One]

I really hope this goes through as shown. What I also really like about these interchanges (and the project in general) is it shows that you can do major highway upgrades within tight footprints. I feel if in other provinces the Steveston interchange would be a huge sprawling monster using up twice the land (or more).

[Marshal]

I agree with all the excitement and am also impressed with the designs.

Grumpy time: These could be reduced/simplified quite a bit so that the 'gold standard' budget could free up money to finish other road projects: finish the SFPR properly, or make the Mary Hill/Laugheed Hwy free flowing to Maple Ridge, as examples, etc.

Do we really need that level of exchange at Steveston Hwy? I thought of this when I squinted and the interchange looks like the meeting of two main freeways. But Steveston Hwy is far from that. It goes east to very little, and very little developable land for the future, and it goes west to a very low growth, low density area.

Here's a thought though: maybe Steveston Hwy will be extended east way out past No 9 Rd. and a connection with the Alex Fraser/Queensborough nexus. That might be a useful.

[adrianroam95]

Here is a short thread on existing examples of dedicated bus lanes that cross over one another to provide access to a central median platform for passengers:

http://humantransit.org/2012/06/request-for-information-busways-that-cross-over-at-stations.html

Some prominent examples in North America include:

• I-110 and I-105 in Los Angeles
• 46th Street and I-35W in Minneapolis

Some points that come to mind:

• Having one central platform instead of two side platforms reduces the physical footprint of the busway and is a good deterrent for criminal behaviour (CPTED).
• Having a bus stop located under a freeway interchange might be unappealing to transit riders due to high noise and air pollution.
• Clear signage and/or traffic control is required at the crossovers to reduce the risk of distracted/negligent drivers crossing into oncoming traffic.

[libtard]

Originally Posted by Marshal

I agree with all the excitement and am also impressed with the designs.

Grumpy time: These could be reduced/simplified quite a bit so that the 'gold standard' budget could free up money to finish other road projects: finish the SFPR properly, or make the Mary Hill/Laugheed Hwy free flowing to Maple Ridge, as examples, etc.

Do we really need that level of exchange at Steveston Hwy? I thought of this when I squinted and the interchange looks like the meeting of two main freeways. But Steveston Hwy is far from that. It goes east to very little, and very little developable land for the future, and it goes west to a very low growth, low density area.

Here's a thought though: maybe Steveston Hwy will be extended east way out past No 9 Rd. and a connection with the Alex Fraser/Queensborough nexus. That might be a useful.

Extending steveston highway that far would never work. And yes this interchange is pivotal. East of 99 gets back up all the way to silvercity. West is even worse, getting backed up all the way to shell road. Unless you've been in this area at rush hour you wouldn't understand

[urbancanadian]

Originally Posted by adrianroam95

• Having one central platform instead of two side platforms reduces the physical footprint of the busway and is a good deterrent for criminal behaviour (CPTED).
• Having a bus stop located under a freeway interchange might be unappealing to transit riders due to high noise and air pollution.
• Clear signage and/or traffic control is required at the crossovers to reduce the risk of distracted/negligent drivers crossing into oncoming traffic.

This would make a strong case for marking the bus-only lanes in the standard red paint.

I still think these areas need to be treated more like bus stations than just bus stops, if that makes sense.