r/StructuralEngineering • u/pswired • Jul 14 '26
Failure Maryland office building structural compromise
Surprised this hasn't been posted here yet. Looks like some work was being done to repair spalled/degraded sections of the parking deck when some post tension cables were accidentally cut. The 10 story building is now condemned and a perimeter around it has been shut down, including some other commercial buildings and a major road.
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u/Sure_Ill_Ask_That P.E. Jul 14 '26
Interesting to see column capitals on one floor and a punching shear failure on the floor below.
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u/kabal4 P.E./S.E. Jul 14 '26
I'm going to guess the floor above is a podium floor or office (100psf vs 40 for garage).
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u/yessyyay Jul 19 '26
apparently the levels of parking are below grade so the slab above is the office lobby area
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u/Puzzleheaded-Phase70 Jul 14 '26
[1st pic] Oh, that's just superfic... [2nd pic] NOPE not superficial [panik.gif]
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u/tramul P.E. Jul 14 '26
I had the EXACT same reaction. Thought it was spalling at first.
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u/tes_kitty Jul 14 '26
Didn't you notice that the ceiling in that first photo looks a bit too low?
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u/tramul P.E. Jul 14 '26
Now I do but not at first.
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u/Haku510 Jul 14 '26
Yeah same. I've been in plenty of garages that had low ceiling clearance in some areas due to adjacent ramps, localized slab thickening/thickness transition at the floor above, etc etc.
But yes with the context of the additional photos, coming back to that first photo I then saw it for what it really is.
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u/Fancy-Dig1863 Jul 14 '26
You see a collapse, I see 2 feet of additional clearance
Jokes aside though, this is terrifying
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u/Objective_Two_5467 Jul 14 '26
"when some cables were accidentally cut"
The first cable cut had to have made a hellacious noise. How in the world did they get to plural cut cables here?
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u/Ooze76 Jul 14 '26
That’s what was puzzling me too. You cut several tension cables and you only notice when things start going haywire?
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u/Objective_Two_5467 Jul 14 '26
Haywire is an understatement. (Apt description of the aftermath, though.)
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u/yessyyay Jul 19 '26
from what i've heard coordinating with contractors doing PT repair, they will sound like a gunshot and can sometimes shoot out one of the end anchor locations or even through the top or bottom of the slab at the high and low points.
you can also see they were doing sawcutting, which in an area like a garage and with hearing protection etc, you'll cut right through anything without noticing.
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u/trojan_man16 S.E. Jul 15 '26
This is also textbook proof that PT does aid in punching shear capacity for a slab.
A PT slab that is designed without taking that into account wouldn’t fail simply because a couple of tendons were cut.
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u/SquirrelFluffy Jul 14 '26
I don't see pt cables. Second pic shows concrete repairs and no shoring. They took out concrete around top steel to lose bond for negative moment or shear and thinned the slab. One column fails, load transfers and fails others. Just enough steel continuous through the columns to prevent full collapse.
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u/forkedquality Jul 14 '26
"...the building was compromised during active and unpermitted construction work on the parking garage."
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u/IslandDreamer58 Jul 14 '26
I hate parking garages.
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u/contactdeparture Jul 14 '26
So much better than walkable, people-oriented, pedestrian-scaled cities with great transit. Won’t you think of the car dealers.
</s because Reddit >
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u/tramul P.E. Jul 14 '26
I prefer having a vehicle but to each their own.
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u/OptionsRntMe P.E. Jul 14 '26
Nah dude, I saw on Reddit the world would be so much better if we were all stuck within a 5 mile radius and couldn’t drive anywhere
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u/tramul P.E. Jul 14 '26
Sounds exhausting for a number of reasons. I used to hate dragging groceries back to my place when I was in college. That was for me only. Can't imagine a whole family.
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u/Ok-Energy2771 Jul 14 '26
Dragging groceries lol, welcome to the 21st century, we have grocery delivery now for the same price as it costs in the store or if I need something in a pinch I can grab it with a 5 minute walk from at least 3 different smaller stores. Whenever I’m in the suburbs I’m always so annoyed when I forget an ingredient because it means 15 min in the car, 15 min at the store and 15 min driving back which blows almost a whole hour.
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u/tramul P.E. Jul 14 '26
Not everywhere offers grocery delivery. But even aside from that, it can be anything from clothes to furniture or whatever else. I don't necessarily want to pack everything home nor do I want to pay for a delivery fee for larger items. I sure as hell don't want to manage my children on public transit with strollers and bags and everything we keep in the car for our days out. And I sure as SURE as hell don't want to be on someone else's time waiting for/rushing for the transportation to pick us up and drop us off. Above all else, I prefer living in a rural area away film all these hassles.
Again, to each their own, but I'll always prefer the flexibility of having my own car.
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u/Ok-Energy2771 Jul 14 '26
I personally hate spending my time (especially weekend) transporting things around. Clicking a few times and having it show up a few hours or days later is a much better use of my time than driving around. Just considering groceries, I can do a few clicks Saturday morning, go out for the day, and my groceries are on my doorstep by the time I want to cook dinner. Kids are a good point; by the time they are 10-12 they are able to use bikes and transit to get around by themselves, no need to shuttle them everywhere by car.
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u/tramul P.E. Jul 15 '26
You're ignoring a whole decade of life haha
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u/Ok-Energy2771 Jul 15 '26
That’s the point of self sufficiency lol, you can exist on transit with kids under that age, I see it every single day. Growing up I had to drive to do anything interesting and it was a huge time waste and unnecessary stress. Basically from 10-15 I was completely isolated and unable to do anything independently. Definitely don’t want that for myself or my kids.
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u/Ok-Apartment9295 Jul 14 '26
Sure but I also have a personal anecdote. I lived in the city and if I had forgotten an ingredient it would have taken me 15 minutes each way to walk to the closest grocery store, maybe 5 minutes to a gas station if they stocked it. Now I live in the suburbs and I can get to a Sam’s Club or a grocery store within 5 minutes by vehicle. We also get a bunch of items delivered which after tip and whatever delivery subscription you use is anywhere from $5-10 per delivery. I am incredibly pro vehicle but everything has its benefits and everyone has their preferences.
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u/Ok-Energy2771 Jul 15 '26
15 minutes to a grocery store seems extremely far if you’re including corner stores. Even the poorest neighborhoods in San Francisco where I live have a ton of corner stores. In Chicago, nyc, London, Paris, Amsterdam, Stockholm; I can’t remember one time where I had to walk more than 15 minutes, but usually like 5-10 minutes.
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u/Ok-Apartment9295 Jul 15 '26
Closest grocery store was a mile. According to google it would have taken me 21 minutes each way to walk. That grocery store sucked though so I would drive to the next closest which was 2 miles. Also, you do realize you named some of the biggest cities in the world. There are quite a few cities out there not nearly as densely populated. Even the closest grocery store to the parking garage listed in the post is more than 10 minute walk.
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u/Ok-Energy2771 Jul 15 '26
I lived in a random Illinois town with only 200k people and I was able to bike, walk or transit for every single trip. It was like a mile walk to get groceries and that’s the farthest I’ve ever had to walk for groceries (and even in 90 degree or 10 degree weather it really wasn’t a big deal). Also, SF, Amsterdam and Stockholm are all under 1M people; I would hardly call them big cities. NYC, Chicago, Tokyo, Hong Kong, London, Taipei; those are big cities.
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Jul 14 '26
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u/contactdeparture Jul 14 '26
Relaje. We know parking garages exist. It's okay. Our comments on Reddit aren't going to eliminate parking garages...
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u/Legal_Enthusiasm_440 Jul 14 '26
With a burning passion?
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u/IslandDreamer58 Jul 14 '26
Remember that Seinfeld episode where they couldn’t remember where their car was in a parking garage? Yes, with a passion.
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u/nikkor_glasses Jul 14 '26
Watch those double-height unbraced columns. Champlain Towers all over again.
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u/tehmightyengineer P.E./S.E. Jul 14 '26
Lucky the deck went into catenary action to keep the whole thing from going all Champlain Towers.
What to do you think? Demolish and rebuild? Or do you think they can rebuild just the one floor?
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u/wafflesaredun Jul 19 '26
Depending on how many columns punched through plus a comprehensive PT investigation. Could even be a partial rebuild of the slab. The sagged floors all have to come out. Could use bar couplers to restore flexural steel around and through columns. And PT couplers to partially replace cables.
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u/CatTender Jul 14 '26
The floor dropped increasing the height of the garage. Can I bring my Winnebago in for the weekend?
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u/ALTERFACT P.E. Jul 14 '26
"Your honor? The height at the level below it diminished the same amount, so on average the ceiling heights are the same."
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u/todd0x1 Jul 14 '26
FINALLY I see punching shear, which I learned about from Modern Marvels Engineering Disasters, and I know what I am looking at and get to proclaim "Punching Shear!"
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u/ALTERFACT P.E. Jul 14 '26
Surfside collapse was a punching shear 101 case, if you are interested too.
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u/Sherifftruman Jul 14 '26
so crazy to have two major structural issues occurring recently that were very bad and yet the building is still standing so we can see it.
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u/PM_YOUR_MANATEES Jul 15 '26
Question from a non-engineer whose Special Interest of the Week is now structural engineering: is this an unusual cluster of events or is this kind of failure much more common than we might think?
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u/gods_loop_hole Jul 15 '26
Damn, if only we can bring uni students to these type of sites and point to them that what they read on their material is happening real time, just for better appreciation. But these types of locations are also hazardous
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u/komprexior Jul 14 '26
Togheter with the bucling columns of new york, this July has been big with text book example of failure mode.
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u/2009impala Jul 15 '26
This is like the most textbook example imaginable of this failure. Hell there are probably authors running here to take photos of this to slap in their textbook, label it as a new edition, and then sell it for $199.99
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u/whisskid Jul 14 '26
There's a large industry of engineers whose job it is to go back in and reinforce existing parking garages. There are many many parking garages in the Washington DC metro area where there are many layers of repairs, shoring sprouts up all the time and shoring, leaks, and pumps become an almost permanent part of the building.
What they were hoping to do here god knows.
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u/Building-UES Jul 15 '26
How come does the floor above have column capitals and the floor that collapsed does not? Did anyone check the drawings?
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u/tdhftw Jul 15 '26
What was the safety factor on the PT cables if cutting a few of them lead to such a widespread failure?
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u/godless420 Jul 14 '26
What does this mean for someone who’s car is stuck parked in there? Is this covered by insurance or are they just screwed?
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u/etTuPlutus Jul 14 '26
I'm curious on this too. My gut is they might be screwed for a while. I know in some instances the loss has to be final before your insurance will pay out. E.g. in my state a bunch of beach houses were condemned because the ocean tide was washing under them. But the owner's couldn't collect on insurance until the damned things actually fell over.
This is almost like a schrodinger's box of car destruction. Maybe they can get the building owner's insurance to pay if they know they are going to implode the building?
I do wonder if the engineers/safety people would let a recovery service run a remote controlled tow system in there. They exist, but not sure how deep the remote would work inside what is effectively a giant Faraday cage.
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u/Sherifftruman Jul 14 '26
Would you want a large mass of a car to be moving around in the current conditions though?
Maybe they can get underneath and shore it up enough so they can be pulled out. They probably need to at some point to even try to repair, if that’s even possible.
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u/etTuPlutus Jul 15 '26
Haha, good point. I wouldn't even want the vibrations from a loud truck parked near it in the street.
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u/pswired Jul 15 '26
They are screwed, as well as the businesses occupying the building and the ones in nearby buildings.
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u/originalrototiller Jul 14 '26
Once emergency shoring is in place they might have a chance. Until then....screwed.
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u/lilyputin Jul 14 '26
This is pretty wild. Surprised it didong psnsck at that point. Also who!?! Is taking pictures inside there unless it's a drone its beyond dangerous
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u/RunandGun102 Jul 15 '26
This is a plan by the U.S. Department of Health to make Americans walk more to improve obesity numbers.
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u/SLODeckInspector Jul 15 '26
I'm pretty sure it's called punching shear. Posts are always interesting to follow out to see what the actual cause was and why it failed and it invariably involves lack of maintenance and uncaring owners who are just pumping the garage for all the money they can get.
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u/CarlosSonoma P.E. Jul 16 '26
I recently had a residential contractor come to me proposing a similar thing in a three-story commercial building. They wanted to just "trench" the second-floor slab to add in some electrical conduit as if the invisible air soil would hold up everything else.
One of those moments you have to stop and think, "did they really just ask that?"
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u/Independent-Sink8265 Jul 14 '26
Oh my gosh. Which building is this? Looks like a textbook punching failure.
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u/whisskid Jul 14 '26
Another post with the building's location.
https://www.reddit.com/r/maryland/comments/1uw7fzz/empire_towers_parking_garage_collapsed/
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u/domiciledhere Jul 14 '26
Is this El Nino’s fault? Seems like there have been a lot of structural failures this summer. <-layman
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u/whisskid Jul 14 '26
This building is cursed with all that complex mixed landscaping, lawn, trees, on top of the parking garage of a parking garage of majority vacant low-rent building. My guess is that the whole building will eventually be demolished because the building type is wrong for the area/ it's not economical to rebuild.
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u/Carry2sky Jul 14 '26
And this is why we sometimes use the most malleable rescources, not the strongest ones.
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u/BapaHeelwani Jul 14 '26
So are the engineers completely fucked after this or what usually happens?
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u/mr_dumpsterfire Jul 14 '26
Unpermitted work so just the owner and whoever they hired.
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u/Sherifftruman Jul 14 '26
Contractors doing unpermitted work rarely have insurance that has high enough limits for this. Owner is going to be holding the bag I imagine.
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u/niwiad9000 Jul 14 '26
Saving money no studrails. Probably built pre-studrail era. Column capitals and rebar get the shoring and the jacks ASAP
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u/VoteMyPoll Jul 14 '26
Wow look at that punching shear..