"Strong focus on aesthetics" contributed to collapse of Norway timber bridge
dezeen.com
dezeen.com
The ironic part is "The bridge replaced a steel truss bridge built in 1895 at the same location". Engineers in 1895 knew how to use steel trusses and built a bridge that lasted 100+ years, and in 2012 they decided to use glued wooden beams and it fell apart in 10 years.
Well perhaps Plan Arkitekter and Norconsult can take a trip to the archives and see what the engineers in 1895 knew before building any more structures.
It's a little too strong of a claim. Plenty of poorly designed steel bridges from the 19th century have collapsed as well, despite the superior material.
That's true. But I only meant that particular bridge, which did last for 100+ years. So, when the architects and the engineers go to the archives to relearn a few things, they can focus on the ones which haven't collapsed.
The old one wasn’t wide while the new one had two lanes and a normal sized sidewalk.
Rivers produce lots of moisture.
Corrosion weakens the steel. It's literally the metal flaking away.
All steel corrodes. Even stainless.
Once corrosion sets in and the outside of the metal starts to pit, the corrosion speeds up drastically. (The old area vs volume thing, same thing that makes lump coal difficult to ignite while aerosolized coal dust is practically an explosive).
Here's a modern US bridge - all steel - that collapsed in Pittsburgh two years ago. In some areas over 80% of the original steel thinkness was gone after 49 years.
As always, lack of maintenance and poor design choices (use of corten steel) are the culprit.
"There are more than 617,000 bridges across the United States. Currently, 42% of all bridges are at least 50 years old, and 46,154, or 7.5% of the nation’s bridges, are considered structurally deficient, meaning they are in “poor” condition. Unfortunately, 178 million trips are taken across these structurally deficient bridges every day. In recent years, though, as the average age of America’s bridges increases to 44 years, the number of structurally deficient bridges has continued to decline; however, the rate of improvements has slowed. A recent estimate for the nation’s backlog of bridge repair needs is $125 billion. We need to increase spending on bridge rehabilitation from $14.4 billion annually to $22.7 billion annually, or by 58%, if we are to improve the condition. At the current rate of investment, it will take until 2071 to make all of the repairs that are currently necessary, and the additional deterioration over the next 50 years will become overwhelming."
ETA: Also, the ones that have survived aren't road bridges. They're either railway bridges (and thus were built strong in the first place) or have been relegated to historic preservation/pedestrian use only. Modern cars and (especially commercial) trucks are far heavier than early vehicles. A road bridge built in the 1850s was only designed to carry foot traffic and horsedrawn vehicles.
The purpose of the hull is to protect the paint.
The purpose of the reactor is to drive the paint around.
The purpose of the SUBSAFE program is to ensure the paint comes to the surface and will not be lost.
The purpose of the cathodic protection system is to back up the paint.
The purpose of the weapons is to defend the paint.
The purpose of the Special Hull Treatment is to protect the paint.
The purpose of the Vertical Launch System is to destroy those who would do the paint harm.
This page details the other continuous maintenance going-on. [1]https://www.goldengate.org/bridge/bridge-maintenance/
Now that effectively might mean then combing over the bridge end-to-end and painting as needed so what I said might be a distinction without a difference.
This is basic materials engineering.
So again, do you know this specific bridge was replaced for this specific reason, or are you just making stuff up? Because bumping in on a specific question with a generic answer without any knowledge if that applies to this specific case is making stuff up.
The hostile tone is because you're talking complete nonsense with great arrogance.
Sure, novel things should be tried, but in a conservative manner. Overdesign first, then optimize iteratively. Because failure costs lives.
Bridges on the whole are pretty clearly better built and safer today then they were 130 years ago. I don't think there's any significant argument to the contrary. There are outliers in both directions, obviously. The old one at this site looks like it was pretty great. The new one sucked. That doesn't say much about why that was true, just that it was.
For sure, we can each talk about different things. I can talk about ironic things and you can talk about statistics, and we can still be friends!
> That doesn't say much about why that was true, just that it was.
Well, why do you think it sucked?
And why not? In this particular case, the statistics did not justify the expectation that this bridge would be at least as robust as the one it replaced.
There's a general point to be made about engineering progress, but here we have a case which bucks the trend. Speaking in generalities when the topic is a specific incident is a way of missing the point.
I guess that’s what they’re going for when they say aesthetics had too much of a focus?
I don't see how that follows? Lots of steel bridges have failed over the past 130 years. The overwhelming majority of new-built bridges or any material don't fail.
People really, really want this to be about "aesthetics" because it confirms their priors about being smarter than the rest of the world or whatever. I'm just saying that's 100% bunk and that there's zero evidence for that hypothesis.
Architecture has had a "strong focus on aesthetics" since the very first stones were piled up to make a temple. Let's not get ahead of ourselves here.
Disagree. In late 19th century steel girder bridges were well understood and many of them survive to this day.
They were usually replaced due to changed demands (wider roads, heavier loads), not because of failure.
Or is your claim a mere circular argument, since we can deduce that a steel bridge was poorly designed if it has since collapsed?
This fad has now passed and there have been several news stories about what a bad idea it was. I guess they were trying to get back to using more natural materials.
It sounds like they didn't do it right, though.
https://www.di.se/hallbart-naringsliv/trahustrenden-nar-nya-...
https://www.tmf.se/bransch-naringspolitik/branschutveckling/...
The trend goes back to 2014 even, so it wouldn't surprise me if this wooden bridge built in 2012 was part of that whole wave.
Well, was.
Sarcasm aside, I see more beauty in doing something well than whatever this was. Are they hiring art students to build bridges now?
Tretten Bridge was designed while building regulations in Norway were in transition from a national system to European codes.
Provisions for this transitional period enabled the project to follow the older national standards, which unlike the Eurocodes did not account for block shear failure.(It's similar to the more readily/well understood "peer pressure", but even more insidious.)
https://www.nsia.no/Road/Published-reports/2024-03
I translated some of the norweigan paragraps that include "estetik" but I can't figure out if they mean "they should have used steel" or they mean "the diagonal members should change direction to keep them in compression" or both.
> En kombinert stålbjelkebru med betongdekke var mulig, men ble utelukket på grunn av estetikken og begrensningene i veigeometrien under og på brua.
which states that aesthetics and road geometry together ruled out a combined steel and concrete bridge.
there's also:
> Artikkelen beskriver avslutningsvis at det i pre-designfasen var flere retningslinjer knyttet til utformingen av brua. Videre står det at teamet som prosjekterte brua ble påvirket av andre prosjekter på den aktuelle tiden, og at Oppland fylke var et skogsbruksfylke der tre har vært et viktig byggemateriale. Dette, kombinert med fordelene av det lette dekket, medførte at en trebru var det beste alternativet. Kombinasjonen av tre og stål gjorde det også mulig å utforme brua som ønsket, uten ekstra avstivning ved aksene.
But in the end the above just amounts to "they could have built a conventional bridge but wanted something prettier": basically aesthetics contributed to the collapse because it was the primary reason they built something novel.
Had there instead been some site specific geometry that forced a novel solution, one wonders if they had blamed that...
Here's one that combines both techniques:
https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2F...
What was done instead concentrated the tension stress onto a small central core section of the member, with rest transferred to wood grain-aligned, therefore weak, sheer faces within the timber.
Thanks for the video: To anyone who's spent some time working with wooden garden gates, that's enough to tell the story.
No, you just have to pay a lot more for it, and civil projects don't typically allow for endlessly ballooning budgets.
You can strongly value two (or more) things, but when you decide to focus on something, as I understand the term, you necessarily preclude focusing on another thing.
On second thought, a camera can only focus on one field. So it would make sense if our language only allowed one focus. But what if we had multiple cameras? Or multiple teams or engineers designing a bridge?
Have we gone too far? lol
It's almost as if someone accidentally flipped the materials -- the members that work in compression are were made of metal, the members under tension, out of lumber. That's the opposite of what each material is naturally strong at.
Steel is similar in strength both ways, although it varies a lot depending on how it was annealed. (The harder the metal the better compression is vs tensile.)
Wood can easily be built up into a much larger cross-section than steel for the same cost and less weight, so it makes sense to use it for compression loads.
Though the FIU one collapsed within a week of the fatally flawed span first being installed.
And from my recollection of coverage at the time - FIU's administrative pressure to deliver their dramatic & leading-edge-construction bridge, quick and cheap, lead to all sorts of corner cutting in the engineering & fabrication.
The bridge could have been designed correctly. But the fundamental issue was the bridge didn't need to exist.
It's also very telling for you to condense "a freeway and a gigantic parking lot" down to "one single driver ever." Five motorists wouldn't have been killed by the collapse alone if "one single driver" was the only one who ever used it.
Here's the bridge in Norway, before collapse.[1] That is something that should never have been made of wood.
[1] https://static.dezeen.com/uploads/2022/08/tretten-bridge-nor...
> "These framework conditions, combined with the choice of material and a strong focus on aesthetics, contributed to the structure not being robust."
Given that it doesn't look that remarkable it seems odd that a little asymmetry couldn't be accounted for. Or was someone out there saying "we'll never build symmetric bridges, our river is too good for them..." Because the rest of the article makes it sound more like an engineering failure.
> "A short construction period, span lengths and reuse of existing foundation were framework conditions for the planning of the bridge," [the report by the NSIA] continued.
I understand why a design website would emphasize the design aspects though.
Architect's first commandment should be to strive to a perfect integration of beauty, usefulness and durability. There are many real world examples, so it's not a trade-off.
Plus, that "strong focus on aesthetics" seem to be a throwaway comment in the report, and it is disputed by the design studio who built the bridge.
The Pantheon in Rome is an especially nice sign of contradiction, but it is hardly alone.
We are human beings, not some consumerist homo economicus that exists merely to eat, shit, drink, and copulate and in a bestial manner. Let us care about the beauty of our environment. This can be done even within means. Beauty is a transcendental. Those who attack it, or insult it, who denigrate it, who dismiss it are misanthropes and enemies of the entire human race.
That does not strictly mean that the two are always in conflict.
I am more than a machine without feeling, but I prefer my bridges to not collapse when I drive on them, no matter how pretty they are.
So they at least need to wash it and put on a roof that prevents it from happening again.
Apart from that, this building is fine overall.
It's odd though, because I would call this building sterilized and flattened as well!
I think this about lots of 'brutalist' buildings: theyre gorgeous as is and might be improved a bit and receive less hate if they used more materials than just concrete and glass. Brick, Timber, and stone even after all people love all the Frank Loyd Wright stuff and he used plenty of raw materials.
But the streaks, oh no, that's just foul lol. Weathering is nice on a buildings, but not grotesquely like that
Architects aren't structural engineers and only in dialogue good infrastructure can be created.
So many new buildings seem to think that all space needs to be given over to being impressive, instead of dedicated to the people that work in it.
https://upload.wikimedia.org/wikipedia/commons/thumb/4/4f/20...
https://en.wikipedia.org/wiki/File:2023-09-04_13_02_10_View_...
I'd say it is a very conventional (& rock-solid) steel through-truss bridge, with a bunch of neon 'tude tacked onto its side.