"Six Amazon.com Inc (AMZN.O) workers were confirmed dead on Saturday after a series of tornadoes roared through a warehouse near St Louis, ripping off its roof and causing 11-inch thick concrete walls longer than football fields to collapse on themselves."
Horrific.
A wall that size cannot possibly survive a big wind.
Looking at the photos it seems like a massive building and the tornado just sliced straight through it. I’m not sure what you can do about that that’s reasonable?
A candle factory was completely leveled. Dozens dead. Many still missing.
I am not sure about US warehouses, but somewhere else it will surely will.
Any seismic regulation would've probably completely blasted a building where roof is not held in place in tension. In general, remains seem to lack any continuous reinforcement in between panels. Only flimsy fasteners held them together.
USA is a land of contradictions, and its building codes are no exception.
They write 100 pages sections of building codes regarding fire resistance, down to mandating which kinds of doorknobs can be installed, and then allow people building stuff from plywood.
Same for building in hurricane/tornado areas. It's absolutely nobrainer how to build buildings capable of withstanding any imaginable hurricane.
But instead of just banning anything not built from reinforced concrete, or steel, they keep trying to "rationalise" building methods which would still have zero chances surviving a tornado, even if laden with every reinforcement imaginable.
Most buildings are in this category, and it make sense. This is not where the fault lies.
Building something to specifically withstand 200mph wind is NOT reasonable. Hurricanes force wind by comparison starts at 74mph and decays quickly inland.
What's the point, though? Statistically, most people who live deep in Tornado Alley will never even see a tornado in their lifetime. Getting hit by one is like winning the bad luck lottery; trying to build all buildings to be tornado proof would be wildly expensive and difficult to justify. Better to focus on good warning systems and making sure shelters are plentiful.
> A properly engineered reinforced concrete building would easily withstand that.
You could build a building like a tank, but it would price most people out of the market. Doors and windows in that structure won't be able to withstand the obscene wind forces however, so everyone inside will still likely be killed by the airborne debris, anyhow. You really wouldn't have time to install steel shutters on the windows and bar all the doors like you'd need to. But hey, the building will remain standing, so that's a win, right?
Instead of all of that, just requiring a small emergency shelter in each home might actually keep the occupants alive.
It's an interesting idea, but I wonder about that. The largest Quonset hut ever built was 54,000 sq ft [1]. The Amazon facility was 1.167 million sq ft.
At that square footage, the semi-circle arc (which is its main wind-deflecting feature) would have to be gigantically tall. It doesn't sound like a feasible geometry at that scale.
Damage scales exponentially with wind speed. Hurricanes max out around ~180MPH. That's the speed of a feisty F3 tornado. You can be "hit" by a hurricane and be fine unless it's the eye or you get some debris in higher winds further out. Any hit from a tornado brings the full force of a thin column of debris whirling at that speed.
> A reinforced concrete should've been easily capable of withstanding a hurricane.
Hurricanes are kinda wimpy, though. Their main claim to fame is sustained winds. A tornado can pack winds pushing 300 mph. Good luck building a warehouse that can take a direct hit from that.
“It’s not that the wind is blowing, it’s what the wind is blowing. If you get hit with a Volvo, it doesn’t really matter how many sit-ups you did that morning.” — Ron White
Hurricanes and tornados are two different phenomena, entirely.
A Category 5 hurricane generally has wind speeds less than 200 mph.
EF5 tornadoes start at 200 mph, and can be well over 300 mph.
Could you design a warehouse (note: not a small storm shelter, but a warehouse, which by definition needs to have very large interior open spaces) that would withstand a 300 mph wind? Maybe.
The budget would be well beyond the reach of any non-military client, though.
To be fair hurricanes and tornadoes are not completely separate phenomena. Hurricanes are know to spawn tornadoes within them and these tornadoes can substantially add to the destruction.
It's much more likely to be hit by a hurricane in Florida? It's also unpractical to build everything to be able to withstand the off chance there's a tornado. You essentially need bunkers.
Better question here is if there are adequate alarm and evacuation plans.
I wonder why they haven't compartmentalized the wall in such a way that in case of structural failure only individual sections will potentially collapse, not the whole thing.
This type of warehouse building is extremely pervasive right now. Having worked in an amazon facility and several other 'modern' warehouses, they all share the same design. It's prefabbed concrete sections held in place by steel support columns. Steel truss structure holding roof with steel I-beams providing support to roof. Any modern warehouse struck by the same inclement weather will suffer the same exact fate.
Will add that the weather affecting this particular facility was extreme by any measure but most facilities that occupy the tornado alley should seriously consider this. My facility had a shelter in place policy in case of inclement weather which basically means, everyone(800-1k people?) huddle into 4, 6 person bathrooms.
Amazon Leased the building I worked in, so kind of removes them from blame of structural failure, but maybe not he decision to occupy the building during known severe weather.
I can't even imagine what it would take to design a warehouse-size building to withstand 200-300 mph winds. Not just expensive, but the engineering required would be pretty significant.
By comparison, I think it is probably fairly straightforward to make office buildings that can stay reasonably intact even with a direct hit. Much more structure to work with.
Look at the photos—the panels that make up the exterior wall are segmented into narrow vertical strips. There’s not much you can do about a direct hit across all the cells.
Horrific.
A wall that size cannot possibly survive a big wind.
Cannot.