On Fri, 10 Aug 2007 00:33:25 -0700, Too_Many_Tools
wrote:

FYI...one of the better discussions on the I35W bridge.

Note that so far it is still just guess work.

TMT


Metal plates examined in bridge collapse By MARTIGA LOHN, Associated
Press Writer

snip
===================
It appears to be due to the design criteria.

The Romans built bridges and roads, some of which are still in
use today so it can be done.

When things are designed to be a cheap/light as possible and be
as quick to erect as possible, it means they have minimal safety
factors and little or no redundancy. As is now well known,
little to no maintenance is performed until the structure is
about to fall down because of diversion of the tax funds to other
uses.

This is a sure recipe for disaster, because any deterioration and
corrosion will reduce the already minimal safety factors to
critical levels.

The only thing that is surprising is that we have not had more
such catastrophes. Like the oil filter ad said a few years back
"pay me now or pay me [a lot more] later."

Given the extreme importance of transportation to our economic
infrastructure, and the degree such transportation is by truck
over the interstate road network, it is lunacy not to maintain
this in reasonable condition.