why insist n a 2 bridge design when 1 can be cheaper

[archangelrichard]

Take a look at the Golden Gate bridge in San Francisco; ignore that it is a suspension bridge, look at the lanes. They did something sneaky; as the day progresses they MOVE the lanes.

At the start of morning rush the traffic is primarily southbound so there are only 2 northbound lanes and the rest are southbound with the exception of an unused spacer lane. The lanes are separated by mobile Lit at night Hazard cones.

As the day progresses, around 9am, crews travel across the bridge moving the cones over 1 lane; first subtracting a south bound lane leaving 2 spacer lanes then adding a northbound lane. They slowly do this again and agan until by 3pm there are 2 southbound lanes and the rest are northbound.

If we build the new bridge as a single surface we have the flexibility to do this - in effect we build a wider bridge than otherwise as we can always change the number of lanes for traffic for commutes or special events (like the 4th of july, etc.) without the high price.

Is anybody listening?

[Chief]

I think they are listening, as the "Transit in a box" concept that was just released suggests. As I understand it from discussing this with the Project Engineers, it is simply not possible to build an earthquake resistant structure like you suggest, that carries everything on one bridge that is constucted of reinforced concrete.

You really can't compare the Golden Gate to the Columbia Crossing because the design parameters are completely different, and the fact the Golden Gate is a cable suspension bridge is exactly why they have the flexibility to do waht you describe with lane shifting.

[Waterbuffalo]

The I 5 bridge is made of a fixed strong steal mesh from the 1900's and the Golden Gate is more of suspension bridge.

During the task force meeting early on, one of the people did mention and asked about building suspension bridge along I-5 and this would go for any bridge in Scappoose you were proposing earlier. Because of the Airplanes that fly along the PDX flight path that starts at the Vancouver Lake lowlands and follows I-5 over the interstate bridges into airport, the FAA has jurisdiction about how HIGH the bridge would have to be allow clearance of the planes.

Think of one or two sets of conning towers on the bridge to hold it up. That is why they will never allow it to be built.

That is why in downtown Vancouver, all development is limited to a certain heigth, same as the current Interstate bridges. Do believe most of this area is limited to 75 ft in height.

Back to the conversation. And the second part would be the tugboats and ships that come into the Ports of Vancouver and Portland. In the same area as your proposed bridge, you would have to get approval not just from FAA, the Ports and many other places, but the just spent a significant amount of money scouring the river to allow bigger and higher ships to come up river into the ports, so they would lose business to other ports that didn't have this river level limitation and scraping potential.

This means that the new I-5 bridge or your proposal would have to fit all of these ships under it, even during high water tables? (not sure exactly on this..)

So its safe to say the suspension bridge was considered and would suffer the same problems the CRCP task force is currently dealing with..

[Chief]

Exactly right WB; excellent review of the current design parameters, and why the design team is recommending what they are...

[Waterbuffalo]

Richard, do some research in the Clarkblog archives.. I do believe we exposed all of this in them. Except the NA not approving of the above plans..

[archangelrichard]

why do people insist on NOT reading what I said. I pointed out to IGNORE the construction, suspension or support as that specifically is NOT RELEVANT. Please read the very first line of the very first post before going off on something that is totally off topic

It is about having a single surface instead of two, and being able to flexibly assign lanes as north or southbound. It would NOT change the height of the structure

as far as not being able to build a single bridge as earthquake resistant as two smaller ones B S. How many such bridges are there in California? In the world, in fault line areas? That comment is nothing but crap. (Yes suspension is more earthquake resistant by definition - it flexes) The height issue has nothing to do with PDX aircraft, it has to do with our little private craft landing field just east of the bridge, so this gets down to private small craft landing field or bridge being earthquake safe? (For those who do not understand this one, I used to live in Phoenix when they were talking about building the new stadium under the flight path of their stadium; they were a lot closer and a lot higher.)

So that gets down to the cost / benefit of moving the airfield from pearson field to elsewhere vs the cost of the bridge - has anyone studied that?

[Chief]

Dick, here is another piece of remedial reading I think you should absorb before commenting any further on this thread...

Five is the Focus... (Read 58 times)

http://clarkblog.org/index.php/topic,784.0.html

[Waterbuffalo]

Weren't movable jersey barriers or this same concept tried on the I-5 bridge area when they were playing with HOV lanes? And why did they stop using them?

Richard, they have used those barriers on the I-5 bridge before.. Just don't remember why they stopped using them.

[Chief]

That's all fine and good WB, but I think Dick's point is that he wants one massive bridge instead of 2 replacement spans. That is an engineering issue, and as it was explained to me almost a year ago, there is no way to make one span to carry I-5 across the river, and accomodate all of the complex interchange work that it has to be melded smoothly into.

This is a nuts and bolts issue that I will trust the Project Engineers on, rather than Dick's demands without any backup whatsoever...

[Waterbuffalo]

Chief, I think he wants to talk about a bridge over another area instead of worrying about the I-5 bridge and its needs. That is his basic premise all along in the threads I have been reading.

Creating a corridor through west Vancouver in some form, flying off Felida or 39th street bluffs, didn't Karma say they were sandstone? Then over two active rail lines and into a active bird sanctuary with some form of pontoons like the I-90 and 520 bridges then over the Columbia River high enough to clear any SHIPS that may call to Port in Portland or Vancouver or Willamette River.

Richard, have you heard the comments about the 520 and I-90 floating bridges that are slowing sinking and breaking apart? Sorry dude but I don't think you understand the history behind that area of Vancouver.

Vancouver Lake is a flood plain for TWO four active rivers, Lewis, Cowlitz, Willamette and Columbia Rivers that come together in under I think 5 miles.

[Chief]

What are you going to hook this system up to"" SR-30 via Sauvie's Island??

Let me hear Dick's detailed straegery for selling that one in Multnomah County!

::)

[Waterbuffalo]

he's still on here.. So let him answer..

[Chief]

uh huh....

I hope you aren't holding your breath WB....that was a classic drive-by.

[archangelrichard]

I posted a long comment on the inability of certain posters to read and comprehend what is being said. comenting down from my last post here:

Chief: what the hell does this "Five is the Focus... " have to do with what I was saying here. Have you read either post? they are not related at all.

Waterbuffalo: NO you did not read the original post. I said nothing about jersey barriers; I said "The lanes are separated by mobile Lit at night Hazard cones."

Chief: This makes no sense at all - "there is no way to make one span to carry I-5 across the river, and accomodate all of the complex interchange work that it has to be melded smoothly into." as one bridge would be in exactly the same place at the exact same height, etc. only slightly narrower as it would not be separated. There is absolutely no logic to that comment, no common sense that it could possibly be true.If one span could not work, two could not work either.

Waterbuffalo: I was thinking along the lines of an additional corridor being a higher priority, not a replacement for a new bridge. We need a better route for trucks that goes around downtown portland as they can never improve the freeways through downtown portland; plus all the benefits that would accrue to an additional route, not the least of which is an alternative to the I-5 corridor during construction of the new bridge and if it were to be damaged in an earthquake. Regardless of what happens with I-5 we need another corridor.

I have NO idea how you got into the notion of pontoons, I certainly did not bring them up. Why did you? Where does this come from? In what way is it related? Maybe this is why you didn't understand what I said, you are carrying in baggage that has no relationship. What does this relate to? Who before you mentioned pontoons? who brought this up? (look, I'm harping on this because you are objecting to things you brought up - they have no relationship to the discussion at hand. So you need to examine the reason you brought them up and why this makes no logical sense)

Chief: Again you can not read what I said ("continue to cross the Columbia just north of the Williamette") instead substituting what you want to believe in and attack that. Next time read what I said and comment / criticize what I said; don't invent your own science fiction.

Waterbuffalo: OK so I have spent 25+ years in computers and I would not make the mistake of assuming that just because someone showed up as logged in that they actually are on their computer or are paying any attention to that screen / tab / window

Chief: that is a genuinely childish comment - which goes along with your arguments. I said this in another thread: People, basic rule of thumb about blogs - if you are not going to read the d$!m thing, don't respond; it only makes you look foolish. Remember,no one can make you look like a fool, that is something you have to do all by yourself. The best anyone else can hope to do is point out just how well you have accomplished this (and IN PRINT! How embarrassing for you.)

If you go back and read my original posts, both in this topic and the others, you can respond to those. They are only ideas. You won't insult me by criticizing them logically, with facts, You only insult yourselves when you can't read the original post and go off in a different direction, especially in print where everyone can read it.

I am sorry for you that you seem to be unable to read any posts that disagree with you, objectively, and respond to what was said; that your replies do not relate to the original post, and that you continue to do this in print.

I can only suggest that you immediately cease making yourselves out to be pretentious fools here and start reading what actually was said, understand it, comprehend it, before continuing to post unrelated materials in some kind of ego-gratification fetish.

I created these threads for some intelligent conversation - to see if these ideas held water. I am still waiting for that.

[karma]

Come on here, when are they going to dig a tunnel across instead of a transit in the box, which is pretty stupid!! I can just see a quake and all those bus folks trapped in the box.

[archangelrichard]

digging a tunnel is incredibly expensive, hard to link to elevated locations (downtown vancouver is all uphill!) and if you think being trapped in a box in an earthquake is bad consider the tunnel.The "box" is really a second deck to the bridge built within the supports; that's all it really is.

[karma]

It's still not safe either place??? It was the King of Couv that wanted to dig a tunnel???

[archangelrichard]

In the mountains between San Jose and Santa Cruz Calif. right about at the summit just beside Holy City sits a railroad tunnel that was being built in 1906 when an earthquake happened.Halway through the tunnel it suddenly shifts left about 12 feet where the earth moved.

No, a tunnel is less safe than a bridge (which can be designed to "flex" a bit)

[karma]

So archangelrichard are you one of those engineers that I would love to pull your license from or are you one of those armchair voices that has little knowledge so that you can spout an agenda of few??

[Waterbuffalo]

"So archangelrichard are you one of those engineers that I would love to pull your license from or are you one of those armchair voices that has little knowledge so that you can spout an agenda of few??"

Gives Karma a hug.. <wink..>

[archangelrichard]

Huh?

what brings on these comments? Fear? Jealousy?

Come on, guys, if you have some logical comment; lets hear it, but lose the childishness. There have been other bridges, tunnels, transit projects in tunnels under a bay; lots of research in this. Just be sure to read the original comment when criticizing it. All this talk about suspension bridges when I specifically stated to ignore the type and focus on the single surface nature; talk about movable barriers when I specifically referred to the cones; speaks to a serious reading comprehension issue And that may be why these comments are never taken seriously.

I still do not see anything that would prevent you from using a single surface for the auto traffic, a lower "in the box" for transit, walkway / bicycles and access to the transit in emergencies / accidents (which was an issue cited in the newspaper). The comment about engineering being different for the on / off ramps really doesn't make much sense - how would they be different? The deal with flexible lanes is you would reduce merging - which is the main slowdown before the bridge - during rush hour; effectively making a wider bridge when needed. This is about cost effectiveness.

[LouisWu]

Huh?

what brings on these comments? Fear? Jealousy?

Come on, guys, if you have some logical comment; lets hear it, but lose the childishness. There have been other bridges, tunnels, transit projects in tunnels under a bay; lots of research in this. Just be sure to read the original comment when criticizing it. All this talk about suspension bridges when I specifically stated to ignore the type and focus on the single surface nature; talk about movable barriers when I specifically referred to the cones; speaks to a serious reading comprehension issue And that may be why these comments are never taken seriously.

I still do not see anything that would prevent you from using a single surface for the auto traffic, a lower "in the box" for transit, walkway / bicycles and access to the transit in emergencies / accidents (which was an issue cited in the newspaper). The comment about engineering being different for the on / off ramps really doesn't make much sense - how would they be different? The deal with flexible lanes is you would reduce merging - which is the main slowdown before the bridge - during rush hour; effectively making a wider bridge when needed. This is about cost effectiveness.


You aren't very perceptive, are you? You were warned yesterday about the tone of your postings, weren't you?

You have five minutes to tell me one good reason why I shouldn't boot your confrontational troll ass out of here.

Louis Wu
Administrator

[Waterbuffalo]

Thanks louis wu and chief.