http://www.businessinsider.com/mysterious-sinkhole-swallows-dozens-of-cars-in-mississippi-2015-11 There are many news articles about the incident, the first ones were calling it a "sink hole" which it's obviously not. It appears a very large culvert which looks to be CMP collapsed, swallowing part of the new IHOP's parking lot. What I don't get is you can't see any remnants of the culvert itself. In the video you can see some geotextile fabric draping into the hole but I would speculate that was used to bridge the existing soils in order to place fill during construction of the new site. What I assume is the soil placed for the new construction is red and the existing soil is brown. The loud boom the patrons heard before the lights went out was probably the underground primary or secondary service (or both) giving way in the cave in and shorting out the transformer. Anyway it's interesting to say the least as to what caused the failure. I wouldn't want to have been part of that construction project..
yeah CM , just heard about it on the radio . This is the first picture I've seen . Are we sure it collapsed ? Could it be bad joints at connections that allowed moving water to suck down the fill under the pavement ?
looks like the pipe imploded into it's self it stopped right at a joint at the edge of the pavement. if you don't back fill it right and compact it to at least above the spring line it has no strength .it barely hold itself up
It's 90 miles from me. I agree, I wouldn't want my name anywhere on that project. My guess is faulty installation of the storm drain in some regard. I can't imagine running CMP under a parking lot in new construction.
It even got as far as the BBC ....... http://www.bbc.co.uk/news/world-us-canada-34763157
It's even on Accuweather's site. Their video looks like drone footage, but at the very beginning, you get a look at the downstream end of the CMP. Here's a screenshot:
Thanks digger , that screenshot puts it all in perspective with the people standing close by . Going to take allot of coffee & pancakes to fix that .
Great screenshot Digger, that shows the culprit. It looks like it's been there for a while. CMP is known for rusting through at the bottom which it looks like it has to some point in the pic. Such a catastrophic failure has me intrigued. Did the new construction compromise it in some way or was the line deteriorated? The lawsuit is going to be a mess.
Even after the legal dust settles It would be a challenge saving the IHOP building to replace the culvert . Drive piling or pour concrete curtain wall of some kind around the building perimeter ? Wonder how long it is ? At least it's still holding at the hi way .
I don't have much experience with culverts, so hopefully this doesn't sound completely stupid What would be the advantage of using this big of CMP over a big RCP? Woudn't the RCP be much stronger structurally?
the weight and cost if you notice thats not round pipe it's kinda egg shaped so you would most likely have to run 2-3 parallel rcp to get the volume because of the shallow cover
No doubt TD, if I owned that building I would be getting some helical piers installed. Since it's a relatively light wood framed building, those piers would do the trick. Personally I see no advantage in using CMP over RCP or ADS properly bedded, other than saving money up front using CMP. Pay now or pay later..
I get lost with some of the abbreviations . CMP - galvanized steel round culvert RCP - concrete round culvert ADS - plastic round culvert Correct ? How about precast box culverts ? http://www.jensenprecast.com/Phoenix-b200/Box-Culvert-p4550/
CMP is corrugated metal pile, doesn't have to be round. RCP is reinforced concrete pipe, doesn't have to be round. ADS is a brand of CPP, corrugated polyethylene pipe, doesn't have to be round.
Hey thanks lumberjack , got it . We just call them steel , plastic , & concrete .
That's correct TD. CMP is metal pipe it can be galvanized, tar coated and I've even seen aluminum. RCP is reinforced concrete pipe and it comes in different classes for loading strength and burial depth. ADS is a brand name as lumberjack pointed out. ADS corners the market, it's kinda like calling a skid a Bobcat. These pipes can be round or elliptical. There's a few pics of elliptical pipe in my thread we did a year or so ago. Pre-cast box culverts come in all shapes, sizes and configurations. I've got a project coming up that is designed to have box culverts, don't know the size or configuration yet but their going to be big.
Yeah CM , I would think the precast box culvert is the best solution on this IHOP disaster in the long run . Although it would be the most expensive up front . The old culvert looks to be 20' in diameter . Do they offer plastic that size ? Also wonder how involved the state will be on the IHOP project with a waterway that big .
Dumpster and loading area for trash truck centered on pipe + what appears to be ruble fill on that end. Catch basin on the other end was it tied into pipe or leaking? Cars the straw that broke the camels back?
Exactly, pipe is essentially a continuous arch that translates a vertical load over the pipe to an outward force in the sides of the pipe, with an elliptical pipe like this it is critical to get the compaction to the springline perfect. Perhaps what happened here is the highway portion of the culvert was installed sometime ago under a county/state contract properly and the site development contractor merely used the same type of pipe to extend the culvert but didn't use the same quality of installation as the highway portion, hence the failure up to the highway. A county full of lawyers have already picked out their new Beemer after seeing this in the news.
I am starting to wish my Dodge 3500 was in that hole! Someone had better shore up that side of the building ASAP. Otherwise, no more pancakes!