
How the steel beams cracked at the new Transbay Terminal - tlb
https://www.mercurynews.com/2018/12/13/how-the-new-salesforce-transit-centers-steel-beams-cracked/amp/
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Gibbon1
This sounds like the kind of failure that happens when designers design
structures to the hairy edge and then small mistakes in fabrication. assembly,
or later design changes push the design into failure.

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cimmanom
It’s kind of fascinating and depressing how culture around this has changed.
The Brooklyn bridge was so overbuilt due to safety concerns that despite being
constructed with bolts that turned out to be far weaker than the ones specced
(due to an unethical supplier), it’s still much stronger than it needs to be,
and capable of surviving modern traffic (and at one time, subway trains)
that’s much more demanding than the horse and foot traffic it was built for
despite occasional decades of neglected maintenance.

If modern structures are designed to within an inch of their tolerances, how
are they going to handle the way we totally fail to maintain our
infrastructure? How are they even going to handle normal wear and tear or
changes in traffic patterns (like the way the past few decades have seen a
shift in dominant personal vehicle types from sedans to far heavier SUVs)?

If we want our infrastructure to last a couple hundred years without being
replaced - instead of a decade or two - shouldn’t we be overbuilding instead
of underbuilding? Isn’t putting ourselves in a position to have to replace
rather than maintain large expensive structures penny-wise/pound-foolish?

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NikolaeVarius
Then people complain about how expensive and over-engineered infrastructure
projects are. Also how are you supposed to know what infra will be relevant in
the future and is even worth overbuilding in the first place?

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cimmanom
Regionally, I can't think of any infrastructure that's under-utilized rather
than over-utilized and under-maintained. There are a couple proposed projects
that would be stupid to build in the first place, let alone over-build; but I
can't think of anything existing that isn't already at or over capacity and
very obviously going to be heavily used for the next 50 years and probably
more.

In fact, our entire transportation network is badly screwed and about to
become far worse because major elements of infrastructure we've been using for
between 70 and 120 years years and have taken for granted has seen
_increasing_ use but has not been sufficiently maintained.

If it had been built with cost-saving instead of robustness in mind, we'd have
had to spend 2/3 as much three times over to rebuild it... or more likely, not
have been able to muster the political will to rebuild it at all and instead
seen our economy fail due to the lack of infrastructure necessary to support
economic activity.

The same goes for our water delivery infrastructure (it's taking 50 years to
build a new tunnel so we can even take the existing ones offline for their
first maintenance in a century), our schools and post offices, and probably a
bunch more things that aren't coming to mind just now.

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walrus01
Holes being cut into structural beams, that aren't in the schematic at all
reminds me a bit of the famous Hyatt walkway collapse:

[https://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse](https://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse)

Basically instead of using one continuous rod, they changed the design on-the-
fly to use multiple shorter rods, connected at the hanging bridge.

[https://www.enr.com/articles/38400-why-engineers-must-
rememb...](https://www.enr.com/articles/38400-why-engineers-must-remember-the-
kansas-city-hyatt-tragedy)

