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06/21/04 String Thing Bridges
A little background on why they NEED (not just want) those
String Thing
Bridges.
Because the Trinity is a floodway, the Corps
of Engineers is prohibited from doing anything that diminishes the flood
carrying capacity of the channel.
So, if you put anything in (let's
say a road --which is the whole reason for this
Trinity Debacle) it will reduce the flood capacity
and you will need to
compensate for that loss of flood capacity.
Sort of like dropping rocks in a pail of water.
If you put something in, you have to take
something out.
To compensate for the reduced carrying capacity with
the road in the Trinity channel, they have to dig the
channel deeper and wider. If you do that, the velocity of the water going
through increases and undermines the piers on the existing bridges or similar
bridges with piers.
So voila, the reason you need an expansion bridge is
so the water can just rush under it without undermining the bridge.
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John Willis:
The writer should have said "suspension"
(not "expansion") bridge.
The existing bridges are supported by
pilings and such.
A "suspension"
bridge are made of string which suspends them from above instead of posts
that support from below.
The writer's point:
* Put roads in the floodplain, the ditch must be made deeper.
* Make the ditch deeper, and the flow in
increased (fluid dynamics).
* Incresed flow undermines any supports
from below.
Hence, the need for strings and
things.
This is an invented problem.
Who in their right
mind will go anywhere near that open sewer, so why
build all this fancy stuff to begin with?
As you know, the answer is only to spend
money -- yours and mine.
If they dp get Federal funding,
they will spend everyone's
money in the country (who pays Federal
taxes!) |
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They always say they want the
bridge to make a statement, but --
What kind of statement is it when you have a bridge
over a sewer?
During the summer, 90% of the flow is upstream
effluent. One would think the less attention drawn to it, the better.
Lorlee Bartos
Editor's comment: How does a flat expansion bridge meet the test for a
navigatable river? Isn't a bridge supposed to arc so a barge can get under
it?
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