Author Topic: Looking for some feedback on bridge layout  (Read 4584 times)

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Ed Kapuscinski

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Looking for some feedback on bridge layout
« on: July 06, 2007, 10:07:56 AM »
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I know it's not secured, but I'd like some feedback on the position of this bridge. Do I have the wing walls setup correctly?

They're not symmetrical, but I don't think that really matters. Right?

What do you all think?




asciibaron

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Re: Looking for some feedback on bridge layout
« Reply #1 on: July 06, 2007, 10:34:18 AM »
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what direction is the water flow?  if it flows from inside the radius, then you need to open the angle of the left retaining wall.

-steve
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tom mann

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Re: Looking for some feedback on bridge layout
« Reply #2 on: July 06, 2007, 10:44:21 AM »
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Yeah Ed, that looks nice and fits in with the theme of your layout.  I think that the walls should be parallel, though.

DKS

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Re: Looking for some feedback on bridge layout
« Reply #3 on: July 06, 2007, 10:57:35 AM »
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I've seen very few real bridges that were 100% symmetrical. But I don't think I've ever seen retaining walls that were quite so parallel, so I would open them up a bit, especially on the side inside the curve. Otherwise, it looks good.

Ed Kapuscinski

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Re: Looking for some feedback on bridge layout
« Reply #4 on: July 06, 2007, 11:21:09 AM »
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Thats what I was thinking too now that I've looked at it from the top down. I'll have to get out the ute knife and do some surgery tonight.

DKS

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Re: Looking for some feedback on bridge layout
« Reply #5 on: July 06, 2007, 12:26:08 PM »
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That's an interesting bridge in that it's a skewed stone arch. Are you going to model the interior? In case you haven't seen one like this, the stonework is usually stepped, as below (showing three courses):



A vaguely similar bridge in real life (although not skewed) to show the angled retaining walls:

« Last Edit: July 06, 2007, 12:39:28 PM by dks2855 »

keystonecrossings

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Re: Looking for some feedback on bridge layout
« Reply #6 on: July 06, 2007, 01:36:23 PM »
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Such bridges definitely do not have to be symmetrical. Nor do the sides need to be parallel... or perpendicular to the track/road above.

However, the wing walls typically will spread on the upstream side. If they don't, that could allow water to get behind them, especially during periods of flooding, and would deteriorate the fill and eventually cause a collapse.
Jerry Britton, PRRT&HS #6111
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up1950s

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Re: Looking for some feedback on bridge layout
« Reply #7 on: July 06, 2007, 02:03:38 PM »
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I would open the wing walls up to a 45 degree angle all around , and add rip rap on the lower edges everywhere , but thats just my liking .


Richie Dost

Ed Kapuscinski

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Re: Looking for some feedback on bridge layout
« Reply #8 on: July 06, 2007, 02:43:53 PM »
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I guess part of the problem is that I'm not sure WHICH is the upstream side.

It's actually just the inlet to a pond, but I guess that means that both sides need to be splayed open more.

Chris333

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Re: Looking for some feedback on bridge layout
« Reply #9 on: July 06, 2007, 02:49:13 PM »
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I'd go with 45 degrees as well and possibly tilt the wing walls back a hair if you like:

BTW I'm standing on the edge of the Mahoning River so this is the non-flow side. This little stream flows into the river behind me.

3rdrail

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Re: Looking for some feedback on bridge layout
« Reply #10 on: July 06, 2007, 02:50:31 PM »
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Ed if it's the only watercourse connected to a pond, it has to flow away from the pond, unless it's the Dead Sea in Israel or the Salton Sea in California. Such ponds are usually fed by an underground spring and have to have a way for the water to eventually escape. Rainwater might also flow from the surrounding land into the pond.

That should make it easier for you.  8)

pnolan48

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Re: Looking for some feedback on bridge layout
« Reply #11 on: July 06, 2007, 04:39:11 PM »
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The wing walls are usually just retaining walls. I'd open them up a bit, but not be bohered with symmetry too much.

John

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Re: Looking for some feedback on bridge layout
« Reply #12 on: July 06, 2007, 04:46:54 PM »
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well .. you better get them on there fast .. looking at your pic .. there is significant erosion under your track :)

DKS

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Re: Looking for some feedback on bridge layout
« Reply #13 on: July 06, 2007, 06:18:37 PM »
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Further to the design of skewed stone arch bridges, here is a great image of one that is not stepped. Quite an engineering feat...

http://www.explorepahistory.com/displayimage.php?imgId=1572

SquirrelHollow

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Re: Looking for some feedback on bridge layout
« Reply #14 on: July 06, 2007, 08:23:46 PM »
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Don't forget the Great Salt Lake.  It has a few inlets, but no outlet.   The only escape method for water is evaporation.  This, in turn, leads to the insane salt and contaminant levels.

Maybe you could model the "Tiny Salt Lake"?
-Robert

Uintah Railway, Utah Railway.