Millennium Line - Broadway Extension: Planning & Pre-Construction

[Zassk]

^ Agreed... we are due for a very large earthquake, much larger than what is discussed at that link/video. It is not likely to matter whether a transit line is at-grade or elevated, built on bedrock or silt, when a 9.0 to 9.5 earthquake hits. The whole metro region will be levelled and we will be essentially starting over. The severity isn't really in question, it is merely a probability question of whether that event will happen within the next 500 years.

[Metro-One]

I guess we should stop building towers as well!

[trofirhen]

Originally Posted by mrjauk

Actually, it's fear-mongering based on corporate propaganda. The video was produced by a company that is trying to inject some fear into a Seattle mayoral race in which the two candidates have similar policy views, except for the fate of the Alaskan Way Viaduct (anyone who has ever been to the western part of downtown Seattle has seen this monstrosity--maybe this is the type of Viaduct some of you would like built out from our downtown to connect to Highway 1).

The construction firm Parsons Brinckerhoff really wants the residents of Seattle to vote for Seattle's own version of the "Big Dig". The "Big Dig", was a massive project that ended up tearing down about 6 kilometres of elevated expressway (I-93), that had to that point separated downtown Boston from its North End. The elevated expressway was replaced by a tunnel that was built beneath the streets of downtown Boston. The "Big Dig" itself was rife with corruption, cronyism, went way over-budget (original 1985 cost was 2.8 Billion USD, and ended up costing 8.8 Billion USD--in 1985 dollars). Moreover, according to the Boston Globe, the project will end up costing an additional 7 Billion USD in interest alone. One thing is for certain, however, the construction industry--including Parsons Brinckerhoff--made out like bandits. Now they want the citizens of Seattle to gift them a new gold mine in the form of a Puget Sound "big dig".

More here:

Originally Posted by mooks28

Oh, I know about Seattle and the viaduct issue (notwithstanding the fact that it is already structurally compromised), but to suggest that Skytrain is bad because it is going to fall down in an earthquake and that this reason is somehow a viable argument against skytrain in the first place is ridiculous. If that was the case, every bridge or elevated structure is an imminent danger and we should all be living in tents. Utterly ridiculous.

Originally Posted by Zassk

^ Agreed... we are due for a very large earthquake, much larger than what is discussed at that link/video. It is not likely to matter whether a transit line is at-grade or elevated, built on bedrock or silt, when a 9.0 to 9.5 earthquake hits. The whole metro region will be levelled and we will be essentially starting over. The severity isn't really in question, it is merely a probability question of whether that event will happen within the next 500 years.

Originally Posted by Metro-One

I guess we should stop building towers as well!

While all that you say MAY be true, one only needs to go back to 1989 and remember the San Francisco earthquake, which was NOT "The Big One."

On the East Bay side, a section of double-decker expressway collapsed, crushing people in their cars; the top deck of the Bay Bridge fell down in
a "hinged" manner with one end holding it to the upper deck; and the upper deck Embarcadero Expressaway right in the city partially collapsed, causing civic leaders to put that in a tunnel.

I wouldn't say this man is fear-mongering for ulterior reasons, but this IS a
seismic region, and Seattle, with its double-level Alaskan Way, has something to be concerned about after what they witnessed in San Fran in 1989.

[deasine]

Originally Posted by Metro-One

I guess we should stop building towers as well!

The funny thing is, if this is arguing about expansion of SkyTrain with regard to the Broadway corridor, it's practically completely irrelevant.

[Metro-One]

The section of freeway that collapsed in San Francisco (actually, it was oakland) was a short span built on top of unconsolidated bay mud and ruble fill (the rubble fill was actually from the previous 1909 earthquake). Although the earthquake was only a M 7.1 at the epicenter, the loose materials the viaduct was built on amplified the shaking, causing liquification, therefore locally producing shaking akin to a M 9.0 earthquake.

Therefore the only area along the skytrain network at this similar level of risk is the Canada Line in Richmond, and the Canada line is brand new, unlike the Oakland 2 level viaduct, therefore it has much higher building standards for earthquakes.

Trust me, i just wrote a huge report on building infrastructure in earthquake zones.

[mooks28]

Yet another reason why no one with a say in transportation planning in this province pays the slightest bit of attention to anything zweisystem says...

[mrjauk]

Originally Posted by deasine

The funny thing is, if this is arguing about expansion of SkyTrain with regard to the Broadway corridor, it's practically completely irrelevant.

I posted a comment to his site (don't know if it's been approved yet by the moderator) that essentially says that the potential earthquake problem is just that much more reason to put the M-line extension to UBC underground.

[The_Henry_Man]

Originally Posted by mrjauk

I posted a comment to his site (don't know if it's been approved yet by the moderator) that essentially says that the potential earthquake problem is just that much more reason to put the M-line extension to UBC underground.

Yup, it's been approved and Zweisystem replied:
Zweisystem replies: Tunnels also pose hazards during earthquakes and have to be specially designed to withstand seismic forces. This may increase the cost of subway construction by a factor of 2. This means a $4 billion subway to UBC may cost as much as $8 billion! I doubt any politicians will OK that.

[Metro-One]

HAHAHAHAHAHAHAHAHAHAHA, 8 BILLION? Where does he get his numbers? Has he ever taken a course in civic engineering before?

[racc]

Originally Posted by The_Henry_Man

Yup, it's been approved and Zweisystem replied:
Zweisystem replies: Tunnels also pose hazards during earthquakes and have to be specially designed to withstand seismic forces. This may increase the cost of subway construction by a factor of 2. This means a $4 billion subway to UBC may cost as much as $8 billion! I doubt any politicians will OK that.

http://www.fhwa.dot.gov/bridge/tunnel/pubs/nhi09010/13.cfm

Tunnels, in general, have performed better during earthquakes than have above ground structures such as bridges and buildings. Tunnel structures are constrained by the surrounding ground and, in general, can not be excited independent of the ground or be subject to strong vibratory amplification, such as the inertial response of a bridge structure during earthquakes. Another factor contributing to the reduced tunnel damage is that the amplitude of seismic ground motion tends to reduce with depth below the ground surface

So, if the earthquake is strong enough to damage a properly designed tunnel, I expect we would have far more problems to worry about than just a damaged subway line, like buildings collapsed on surface LRT trains.

[racc]

Originally Posted by Metro-One

The section of freeway that collapsed in San Francisco (actually, it was oakland) was a short span built on top of unconsolidated bay mud and ruble fill (the rubble fill was actually from the previous 1909 earthquake). Although the earthquake was only a M 7.1 at the epicenter, the loose materials the viaduct was built on amplified the shaking, causing liquification, therefore locally producing shaking akin to a M 9.0 earthquake.

Therefore the only area along the skytrain network at this similar level of risk is the Canada Line in Richmond, and the Canada line is brand new, unlike the Oakland 2 level viaduct, therefore it has much higher building standards for earthquakes.

The Millennium Line in sections of Burnaby was build in areas with "self-levelling muck". In both Richmond and in Burnaby, they used piles in the foundations so that earthquakes should not be much of a problem.

[mrjauk]

Originally Posted by racc

http://www.fhwa.dot.gov/bridge/tunnel/pubs/nhi09010/13.cfm



So, if the earthquake is strong enough to damage a properly designed tunnel, I expect we would have far more problems to worry about than just a damaged subway line, like buildings collapsed on surface LRT trains.

I've spent the last of my precious time paying any attention to zweisystem. He never has argued, nor is there any reasonable expectation that he ever will argue, in good faith. Now some moron will look at his post and spread the message that "an expert" in transportation has claimed that the UBC extension of the M-line will cost 8 million dollars--a number that zweisystem pulled out of his ass.

I agree with what you said; if we ever do have an earthquake strong enough to make a subway tunnel "collapse", then that will be the least of our worries.

[Alex Mackinnon]

By that measure we can say that in order make the LRT earthquake proof we need to spend $200M/km!

Hell cause you know, why not! We'll suspend the train completely from a system of gold plated bungee dampers that make seismic calming music when the train rolls over it.

[Tappen]

Earthquake is also an argument to never build anything from now on in Richmond.

[Millennium2002]

I'm a little annoyed at how two groups that should technically be helping each other in getting rapid transit all over the place are instead bickering over costs, engineering challenges, etc.

For one, light rail is NOT seismic-proof. Even with a small earthquake rails will be deformed such that inspections have to be carried out and train service disrupted. It is a crazy thought to think that it's cheaper to build earthquake-proof foundations throughout the whole stretch. Of course, tunnels do much better in withstanding such an impact so there will be fewer problems.

[Zassk]

Originally Posted by Tappen

Earthquake is also an argument to never build anything from now on in Richmond.

Do not assume that there will be a significantly better survival rate of people & structures in other areas when a 9.0-9.5 magnitude earthquake hits. :-) Structures like the Canada Line, Hwy 91, Oval, or YVR that are built on >200 ft pilings are roughly as safe in Richmond as anywhere else.

Liquefaction is mainly of concern where the silt meets the bedrock, e.g. False Creek Flats or New West - not in the middle of the delta. As for flooding, Richmond is above sea level for most of the tide; a 0.5 m rise in sea level from global warming would still leave it above the low tide mark.

[Metro-One]

I'm a little annoyed at how two groups that should technically be helping each other in getting rapid transit all over the place are instead bickering over costs, engineering challenges, etc.

That is the thing, many of us here support LRT to the Valley, but, the LRT to the valley people and others have continued to bash skytrain in their campaign to serve themselves. This is the problem, they have forced us to fight back.

[kylemacmac]

Streetcars that replace bus lines are not a mobility improvement.

There's an interesting article over at Human Transit that explains this:

http://www.humantransit.org/2009/07/streetcars-an-inconvenient-truth.html

An important fact we should communicate when the idea of LRT on Broadway gets tossed around again in the local media sphere, as we all know it surely will.

[WarrenC12]

Originally Posted by kylemacmac

Streetcars that replace bus lines are not a mobility improvement.

There's an interesting article over at Human Transit that explains this:

http://www.humantransit.org/2009/07/streetcars-an-inconvenient-truth.html

An important fact we should communicate when the idea of LRT on Broadway gets tossed around again in the local media sphere, as we all know it surely will.

Good points. Although "street"car in this instance means something that actually runs right on the street, unlike Vancouver's temporary Olympic line. And things become blurred if/when the fullly planned system is built out, as it is partially on the street, and partially on it's own ROW.

I think the basic argument that needs to be made against LRT along broadway or any other street in Vancouver is this: Buses are, by far, the most flexible and cost efficient option. Rapid transit needs to be grade separated to be effective. End of story!

[twoNeurons]

flexible + cost efficient does not always equal higher ridership

Lack of flexibility increases predictability.

I would love to see human studies... like faced with two choices of equal "value" how many opt one over the other and what kind of person chooses one over the other.

Say, for example... we had electric trolley buses, diesel buses and trams on the same corridor, taking approximately the same time, serving the same destinations ( I know... it's silly )

Do people actually show a preference?

How important is the actual vehicle, if all other factors are more or less the same?

What is this perception worth?

Is there a perceived value validating the increased cost of steel rails?

I've never seen a study like that, but it would be fascinating... instead of relying on anecdotal evidence.