Here is part of the problem as I see it. The builder says that the wals weren't inspected because the walls were "in compliance with industry standards".
I have mentioned it before on this site, and I mention it to anyone who will listen - I don't believe that "industry standards" amount to much. Each element should be designed with its own criteria, loading, and conditions. It should not be acceptable to design a wall in Development B the same as a wall in Development A simply because the wall at Development A is "ok". The soil likely has different properties, capacities, moisture conditions, etc. This is true not only for retaining walls, but virtually all structures and elements within those structures.
You can bet that if this were a medical emergency, dr's would be all over every news station, and making the rounds to daytime talk shows to remind everyone how important their profession is and why only doctors can help with the problem (see all of the dr appearances when the H1N1 scare was big).
What we need is a loud voice in the (structural) engineering community doing the same for us. That would give us greater recognition, quite possibly increase our fee structure, and certainly lead to fewer failures like this.
The fact that news outlets are reporting the "industry standards" thing almost implies that it was accepted by an engineer, but they just didn't get a permit. It needs to be made clear whether-or-not this wall was designed by an engineer, and if it was whether-or-not the construction was as designed (and satisfactory).
I would love nothing more than to turn on my tv tomorrow morning and see our NCSEA president discussing the issues of this failure with someone on Good Morning America.
EIT - He built it according to industry standards - the wall has weepholes. Kidding aside, I pretty much agree with you, but I wouldn't say our industry standards don't amount to much. The builder is using the "industry standard" line because he's a F-----G CROOK! I wouldn't be suprised if right now he's got his brother-in-law preparing a back-dated design & boring logs.
We have a retaining wall project that's being bid now - replacement of a 300' dry rubble wall, up to 30' high with a modular wall. The client's generic spec is based on industry standards since the contractor will select the particular wall system. HOWEVER, we did a subsurface investigation, developed design criteria, and we'll review and approve the design.
Unfortunately, many home builders (at least in northeastern Pennsylvania) are notorious for cutting corners.
As an aside: from the photos it's hard to tell what type of wall it is. It doesn't look like a modular wall or a reinforced earth type. Maybe it's a Home Depot special?
To me it looks like they might have shotcreted the slope and laid stones.
Maybe I'm not familiar enough with the term "industry standard". To me, that means that any wall retaining a certain height can be built with xyz.
I think that's a good starting point, but not sufficient for a final design (or to be built with). With all the safety factors we use it likely works, but is still not a good idea.
Just imagine how under-designed a wall has to be to fail like this. With phi factors, load factors, soil cohesion that is never accounted for, etc. it had to be woefully under-"designed".
I think you might be using "Industry Standard" interchangably with "Industry Practice". Both terms can cause a lot of misunderstanding. John Q. Public has one concept; engineers have another; and lawyers - well, that's a whole 'nother story.
In a court of law, "industry standard" would generally mean:
The Design Code that an engineer would be expected to follow in a particular instance, such as AASHTO, IBC, ACI, etc. For example, you wouldn't expect someone to use AISC Steel Construction Manual to design this wall.
In the absence of a code, a court would look to see what is the accepted standard practice in the area.
An industry practice is more of a "means and methods"; for example on the east coast steel fabricators design connections; in the west the EOR does it. It's things like that.
I am not a structural engineer. I am a native Texan. I have family in the construction business there. Some of these are in the "masonry" business. I put quotes on "masonry" because a very large amount of work done in Texas by residential level builders on stone walls, fences, fireplaces and retaining walls, is as BridgeBuster said above, "a Home Depot special".
This wall appears to be constructed without rebar, and is quite likely "engineered" by the guy on top of the scaffold yelling down, "I need a big flat one, about a foot tall, with an angled right side! And the response being: "Hey got just the one, lemme knock off the bump on top, I'll send it right up!
Most of my experience with this is in west Texas, but I can almost see bridgebuster's second spot-on observation going into action; a new project for "After-The-Fact-Design Incorporated.
This is going to cost somebody big bucks, and ten years down the road, if the lawyers don't get it all, maybe the homeowners might even get some relief.
I agree with bridgebuster that these two terms are probably been used interchangeably but the implication that EIT points out unfortunately seems to be correct as well. I feel that many times it invloves how other people view engineers and engineered work. Many times the media attaches a term or presents the story in a sensationalized matter in order to get viewers or readers. The reporter may not necessarily understand the terms or the language that may be used by the engineer been interviewed. It happens in advertisement as well when the word "engineered" is attached to a product in order to sell more. I wouldn't be surprised if that "home depot special" had the word "engineered" somewhere in there as well.
When I first read the story on yahoo, if I remember correctly, the wall did not have the necessary permit. Now I wonder, how did such a wall be completely built without the permit? I believe the project was been constructed in phases so I would imagine the city inspectors had to be going in and out in the area. And the walls are not your short 3 or 4 ft tall walls, they are alot taller; so shouldn't they have across city staff at some point? At least if I was a plan checker I would have wanted to see each wall engineered for its location.
Here in the San Francisco Bay Area, the current story involves apartment buildings in danger of collapse due to erosion of the cliff fronting the ocean. In this case, mother nature is the driving force but I have been following the story in different networks, and the way that engineered aspects are reported are not necessarily in the fairest possible way to the non-engineering public. Here is a link to this story.
(by the way the link above is for info only, I don't mean to list KTVU as an example of bad reporting or blaming it for the bad reporting practices of others)
CPENG78 mentions something that I was wondering about. How was the wall constructed without the city knowing? If plans have to be submitted and inpsections are taking place, someone with the city should have seen this wall was greater than 4 ft.
My work does not involve residential construction, so I don't know how much inspection is actually done by city authorities. But I have a feeling that not every house in a large development is inspected. These developments and houses are built so rapidly that there's no possible way every one gets inspected as it should.
"Looks like they did a nice job of constructing the rock facing, but forgot to build the retaining wall first."
That's kind of the way things were in southeastern Queens (NYC)for many years. Contractor's did a nice job of putting in catch basins but they forgot to put in MOST of the sewer pipes.
"How was the wall constructed without the city knowing?"
If it's like NYC, there probably isn't one person repsonsible for inspecting everything. Here, the Building Department has numerous groups with a specific inspection function - electrical; plumbing; elevators; cranes; etc. Human nature -wall? not my job.
One thing though in NYC, all of the permits for a building project - and there are many - have to be conspicuously posted at the site for the general public. Builders are usually good about this in order to avoid paying fines. The city is very good about issuing violations because it makes a lot of money from fines.
I sent a letter on to one of the Professional Engineers Associations in Canada regarding a recent fatality; a CMU washroom wall collapsed and killed a youngster in their jurisdiction...
The gist of the letter was that any fatality as a result of construction should immediately open a file for investigation/review. The main purpose of professional associations is to safeguard the public. I heard nothing...
Unintentionally funny excerpt from JStephen's link:
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“In regards to the retaining wall, there were some reports that we previously repaired the retaining wall. Centex did fully rebuild this retaining wall in early 2007 following indications that the wall was not performing to expectations. The decision was made to completely rebuild the wall and substantially reinforce its foundation.”
Get the latest crime reports in your neighborhood with the Statesman's Crime Tracker.
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(I don't think they actually meant to make the crime reports part of this story.)
