I-85. What to Say?
We all know what happened last night and that’s partly what has made writing this post so difficult.
The other difficulty is how utterly unimaginable it should be that one of the most important cities in the world’s richest, most powerful nation has a key element of its infrastructure collapse. Regrettably, America’s infrastructure is in horrible condition and failing (SAD!). In 2014, the American Society of Civil Engineers graded Georgia’s infrastructure a C and our bridges a C-. The 2017 grade hasn’t been announced and I am emailing the ASCE for a comment on last night’s event.
Related to the above: if we had a robust, well-planned mass transit system, that would greatly alleviate the transportation woes that are going to ail Atlantans at least through the summer.
We don’t know yet if this was just a horrible accident or a symptom of something far worse. And candidly I don’t think there’s any one solution. Hopefully this catalyzes policy makers in the state and country to look at our roads and highways and do all that can be done to prevent another collapse, even if it means a big bill for taxpayers.
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It will of course have a damaging effect on the Atlanta core’s economic activity. May even measurable at the state level.
As a Peachtree Gateway resident (DeKalb County north of I-85), my household dines nearly once a week in Midtown. That activity will be moving to Buford Hwy and other places for the summer.
I wouldn’t be surprised if the Spring-Buford Highway connector is restricted to HOV use most if not all of the time while reconstruction is underway.
Current information is that the fire underneath the bridge weakened the structure and it collapsed. No evidence so far of a structural failure.
If we had a massive infrastructure problem in this state we would routinely see structures collapse. In reality, such incidents are rare.
“If we had a massive infrastructure problem in this state we would routinely see structures collapse. In reality, such incidents are rare.”
You know, there is a middle ground between “no problem” and “massive problem,” right? Saying we don’t have an infrastructure problem is either a symptom of blindness or ignorance.
There’s no problem. Only SOME of our bridges and highways fail.
Exactly. I had this same argument with William Perry on FB in the early am hours who decided to grind his familiar ax that if Atlanta hadn’t spent its tax dollars on a new stadium we would have better infrastructure. Unless there’s a plan to rebuild the first few miles of I-85 North of the connector with a solid (non-bridge) structure that went unfunded because of the stadium, it’s hard to connect how spending Atlanta’s hotel motel money on different infrastructure would have changed this at all.
One of the most frustrating parts of making public policy is watching everyone pour their want and/or gripe list onto the most recent current event. Yes, we need infrastructure investment. Using a damn fire under a bridge to “prove” that point dumbs down the debate, cheapens the argument, and ultimately, creates a more cynical public when they realize the people that hold themselves out as watchdogs are abusing the publicity game.
I wasn’t trying to use this to prove that and I hope I didn’t come across that way. I just hope maybe it gives the issue of robust infrastructure spending, along with Trump’s $1-trillion proposal, a little more urgency.
Not taken that way. I’ll be curious as to the cause of the initial “spark”, if you will. Like Dave mentioned, a ton of discretionary spending will be done elsewhere. There will be economic repercussions rippling in places we haven’t even begun to think about.
The initial “spark”. I assure you that I’m not a conspiracy theorist but seriously – the fire started the day prior to the first Braves game making 285 a parking lot… but MARTA works great and CobbLinc has more busses at the ready and getting people to Arts Center Station. And luckily the fired evolved in such a way that not one person was hurt – just inconvenienced.
Something smells besides the smoke…
This was not a structural issue. It was a strategic one with whoever decided years ago that using an essential portion of the infrastructure for a convenient roof was a good idea. At least the homeless they ran out of there couldn’t have ever damaged it quite as bad.
Yes, there is a “middle ground” which is why I said we don’t have a “massive” problem. One of the reasons we passed HB170 in 2015 was to repair/replace older bridges and highways and as a result DOT is already addressing the issue.
“if we had a robust, well-planned mass transit system,” – well, it’s not like the people living there have been repeatedly asked to join such a network and refused every single time. /S
If nothing else, can we agree that its not a good idea to store PVC or anything else that can burn underneath an expressway? This is the low hanging fruit that should be addressed yesterday!
My guess is that it will be determined to have been caused by more than one failure. Systems/processes today are such that that is usually the case in event of catastrophe.
I know the media has reported this as “PVC” tube. There are plastics that are not PVC that are also used for conduit when buried underground, notably polyethylene (PE). PVC does not burn well and self-extinguishes. PE burns quite well.
I would not be at all surprised to learn that these were spools of PE conduit for underground raceways for future telecom or electrical lines.
Whatever it is determined to be, we should be able to agree that it isn’t a good idea to store anything that can burn under a bridge, overpass or elevated expressway. Just like I don’t store piles of wood in my house because I know the risks associated with fire and/or termites.
if I remember correctly, there are regs that determine storage (even temporary) under and around infrastructure like bridges. But applicability depends on the jurisdiction. Im not sure whether state or federal comes into play here.
PE makes more sense than improperly treated PVC which is what i thought (PVC is very flammable but is treated with retardants in processing).
Lea, PVC is not very flammable. Its limiting oxygen index is in the 40s. Perhaps you are thinking of a different vinyl, such as PVAc?
The most hurt after the Atlanta core will be Gwinnett County. This will further push the transit planning effort currently underway there, and in my opinion 20 years late to produce the most bang for now half billion or more bucks required to bring transit and TOD to the County.
This kind of event is rare, because storing highly flammable chemicals where they can ignite near concrete supports for a highway is … well, unbelievably stupid.
Any of the supports that reached a temperature high enough to soften steel are structurally unsound now, even if they didn’t give. The construction process uses a kind of steel stretching and compression to give strength to the concrete. If the steel decompresses, the concrete cracks and the game is over.
I took a guess at what this might cost the state’s economy last night. I can run the numbers four different ways and come up with four different figures. GDOT and the ARC will have a better guess, I think. But I suspect it’s at least $2 million a day in lost economic activity, and possibly as high as $6 million.
300,000 cars a day. If half of those cars have to find alternate routes that regularly cost an additional 2 hours a day on the road, then you’ve taken 300,000 hours of productivity away from those people. That’s either less money earned or less money spent in free time. If the typical commuter earns $20 an hour, that’s $6 million a day gone. Some of that loss isn’t going to show up in measurable economic changes — two less hours in front of the TV watching Serial, perhaps — but it’s not zero.
And that doesn’t account for the knock-on effect of adding traffic to other roads, slowing EVERYBODY’s commute on the connector, on I-75 and elsewhere.
$6 million, times 60 days. $360 million before measuring secondary effects.
Some background:
The “original” I-85 in that area was built two generations ago (today’s Buford-Spring connector), roughly between 1952 and 1955, two lanes each way (then-Mayor Hartsfield never foresaw the day where we would need 5 or even 6 lanes each way, but of course back then the Atlanta area was much, much smaller than today). By the early 1980s, traffic was well beyond the capacity of the 1950-s version, so DOT as part of their “Free The Freeways” program built a new 85 just to the north of 85 in that area (the elevated portion perhaps due to the narrow right of way near Monroe Drive and the rock outcrops you see on the old 85 south just below Monroe Drive exit). The viaduct where the fire occurred yesterday may be the longest in the state (though I stand to be corrected on that). Give the age of structures along the old 85 in that area, probably worth an inspection of those old bridges too.
The fire also impacted the Atlanta-Athens CSX rail line that passes under Piedmont and the viaduct—CSX’s main line to the Northeast from Atlanta—the one passing under 85 is a sort of alternative route in the sense that intermodal trains use the cut-through east of Emory that connects the Athens route with the intermodal yard in Reynoldstown. The CSX line that cuts through lower Buckhead generally handles non-intermodal trains and is something of a pressure valve, allowing trains to get to westside of Atlanta without passing through the congested intermodal yard in Reynoldstown.
Hard to see a silver lining, but at least this did not occur on 85 beyond 285, where traffic volume would be even heavier. Not like there is much of a “Plan B” if something on 85 gave out, say, between Jimmy Carter Blvd. and Pleasant Hill Road.
The distance from the road below to the substructure does not look very high, with other road structures to either side. It basically created a kiln effect, superheating the concrete. That fire was very hot, and extended well over an hour at a high level of burn.
The bridge collapsed at the point where pre-tension reinforced pre-cast structural members attached to the beams. You have enough high temperature heat, metal cables lose their tension (while the concrete is also being baked and losing its binding properties) and starts to shift in the structure. The ends where the cables and other rebar are exposed will fail first. The anchors holding the pre-cast structure ends to the beams is also being compromised. Additional cold water will make the concrete brittle. You get enough shifting and the anchors fail, stuff collapses.
That bridge could have been a year old and with enough time/high heat, it would have failed. This is not to say the time could have accelerated due to age and condition. A newer overpass might have a different set of connections that would have lasted longer. However; whatever was under that bridge is not a condition an engineer/architect would have designed to handle. Concrete and steel are non-combustibles, but they are not fireproof. The have a rate for how long it takes to lose integrity at a selected high temperature. If there were high amounts of paint, tar, PE, PVC or other chemicals under that structure, no road way is designed to last more an a few hour before it failed. Even if it had not collapsed, it would be condemned. I would not be surprised if other sections are condemned in the near future.
Anyone else think George Bush planned all of this so that we can go to war in the Middle East? I do. Everyone knows that concrete doesn’t burn. It’s impossible. I bet George Bush had the CIA plant charges on that bridge so it would collapse. The fire was just a distraction.
you jest. but i have already seen a similar post attributing this to a plot by Pres. Obama’s shadow government to somehow embarrass Trump.
*sigh* these are people that vote alongside you and I…
I love the people that tell me all the time “I heard it on the internet. It has to be true.”
I blame this one on the Russians. Putin, no doubt.
I didn’t say concrete burned.
“Concrete and steel are non-combustibles, but they are not fireproof.”
Steel and concrete have a point in which they lose structural stability in a fire. Concrete’s is extremely high but is has one. It can also become brittle if hit with cold water if super hot, reducing that time of stablity. The industry test for the effect of water on a hot object is called a hose steam test. The rate in which it loses stability is measured in hours under a controlled test method through ASTM, ANSI, NFPA, UL or others bending of the industry.
Concrete structure has fire rating which (based on it’s composition and thickness) measure how long in hours it maintains it’s stability. Example, 6″ lightweight concrete floor/ceiling slabs is tested at 4 hours as an industry standard. That’s the time it will take the slab to lose structural stability in a controlled ASTM test. Concrete can also also have various ratings based on how it is assembled or used. A standard 8″ C.M.U. block in a stack bond pattern with min. reinforcing is 1 hour. That same C.M.U. block in a running bond pattern and designed to meet the reinforcing and mortar type requirements of UL No. U905 has a 2 hour rating. Depending on the test or the assembly, concrete is rarely tested over 800 degrees.
So even if you have a tested 2 hour CMU wall build to meet UL design no. U905, holding up a 6″thick 4 hour floor/ceiling assembly, if the burning pile of combustibles in middle of the place is over 1200 degrees, the chances of the concrete assemblies failing before 2 hours (without the addition of a hose stream cold liquids) is high.
I was joking.
Oh.
This is sort of in my wheel house of what my day job involves…
So, the fact that it rained could have possibly made it worse?
From what I saw of the pictures taken this morning, not likely. The fire was directed to the underside of the structure. The road level pours would take any rain and was most likely not as hot to cause structural issues. The damage would be more cosmetic. A 1 1/2 hose stream puts out large amounts of water or foam directly on to the hottest parts of the fire which in this case is the major load bearing structure.
http://www.wsbtv.com/news/photos/gallery-i-85-collapse-aftermath/507896041#
Look at pic no 3. The concrete become brittle enough that it fell off the steel reinforcing in the concrete poured in place column. The beam is structurally damaged. The road level does not have any visual damage in this picture. The poured side guards of the road above is pitted, and some of the rebar pattern can be seen that may have some structural damage. It’s not a major load bearing element and will be replaced unless that overpass also has structural damage.
Think of it like a piece of glass cookware holding a chicken roasting in an oven. You add a little liquid at a time over the chicken your fine. Pour a full cup right out of the refrigerator directly onto the hot glass your going to crack the dish.
As someone who lives in the area I can tell you its a HOT mess on the surface roads. All of 85 traffic is exiting onto Cheshire Br Rd. All of 400 is exiting in almost the same place on Sidney Marcus. All the roads that cross Cheshire Br Rd (Lavista, Sheridan, etc.) are backed up almost a half mile pointed towards Cheshire Br.
If there is a silver lining, perhaps the guys at GA Tech can rig up a study of how people adapt to losing freeway access. Hopefully they can learn something valuable from it.
As all things people will adapt.
Thank God it rained last night and the wind was blowing the smoke away from my area.
This has been studied (and done) elsewhere!
http://gizmodo.com/6-freeway-removals-that-changed-their-cities-forever-1548314937
https://www.scientificamerican.com/article/removing-roads-and-traffic-lights/
I meant in “real time”
I’d also say that those MARTA Park and Ride lots will be full the next couple of months
It just took me 1 1/2 hours to get from Sage Hill area (Briarcliff and Johnson Rd) to Home Depot on Lindbergh and back…this is by no means sustainable. Every street headed in the direction of Cheshire Bridge Rd is backed up for miles
Three arrested in connection w fire. If true, God what have you people done???
The U.S. has unfavorable attention for being one of the worst nations in the world in cost and time building infrastructure due to multiple negative factors, regulation, corruption, relationships, unions, political indecision…….
Charts in major publications are ugly.
On the lighter side msybe we can get China to help:
https://m.youtube.com/watch?v=BW9xycnEU3o
“regulation, corruption, relationships, unions, political indecision…….”
I don’t know how to measure it, but I would think the biggest reason we don’t spend money on this stuff is because so many people want their taxes cut, so there is no money.
regulation- who would oppose our infrastructure improvements because of regulations? Sure it drives up costs a bit, but for good reason!
corruption- how does this prevent infrastructure from being done? I would think it would add motivation to do it.
relationships- again, how is this a hindrance?
political indecision- the indecision only comes from those who don’t think the government can do anything right and/or don’t want to spend any money on anything other than, well, anything.
Many still think “trickle down” works when you give corporations bigger profits, but it usually doesn’t. It does work when when you spend that money you didn’t give away in tax breaks on building a better community that attracts companies and workers. There is a reason why the places with the highest tax rates are also the places with the best economies and highest standard of living. (That’s not to say there is no limit. You can tax too much and this has been studied extensively of course, but I don’t feel up to researching that right now.)