Wind Turbine Collapse

[ARS97]

This happened in my neck of the woods last night:

http://www.wjactv.com/news/features...tra-w-pa-wind-turbine-falls-ground-1209.shtml

Although it's from a distance, it looks like a possible group anchor failure (cone). There's a clean cone of concrete still attached to the base. What's odd is that there doesn't appear to be any rebar sticking out. Plain concrete footer?

I just thought it was interesting.....

 

[msquared48]

Were there high winds in the area, or do you know?

Mike McCann
MMC Engineering

 

[ARS97]

I live about 30 miles southeast, up in the mountains of Somerset County, and I didn't notice anything abnormal.

 

[rb1957]

looking at how the blades have ended up, it doesn't look like it was turning much at the time.

maybe it was a "climate terrorist" ?

Quando Omni Flunkus Moritati

 

[ARS97]

rb1957 - I seriously doubt it.....unless some lib was upset at all of the birds it was killing....lol

 

[azcats]

A bit more detail here.

Link

 

[JLNJ]

The foundation details I've seen for those have really, really long anchor rods amidst a huge grillage of foundation steel. Hard to imagine a failure cone. But that's what it looks like.

 

[JStephen]

See the little video here, about 1:09 in shows the foundation.

Odd thing. If ten of them have been in operation for 10 or 12 years, it couldn't have been TOO underdesigned.

 

[ARS97]

JLNJ - you said that you've seen some foundation details for these wind turbines. I would imagine that the foundation type varies (shallow mat or deep caissons), but have you ever seen any plain concrete called out? Although the video is from a distance, I'm just shocked at how smooth the cone appears to be and from what I can tell, there's no visible rebar sticking out. If rebar was present, that cone wouldn't have sheared off the bars clean.....I would expect some visible elongated bars sticking out. Surely this isn't a case of a contractor saving some cash by "forgetting" the rebar......if so, I doubt they'll be doing any business in the near future.

 

[moltenmetal]

Wow, sounds like the complete absence of construction management and inspection, if rebar was entirely forgotten...and even a chemical engineer has a hard time imagining a foundation like that could survive without rebar!

 

[ARS97]

moltenmetal - that's pure speculation on my part based on a grainy video from a distance. I agree, it's hard to imagine, but you never know.

 

[ztengguy]

These pics show maybe some rebar. Hard to really tell.

http://www.wpxi.com/gallery/news/local/wind-turbine-topples-over-fayette-county/gCG6y/#4371208

 

[ARS97]

ztengguy - I think that's electrical conduit/wires......but who knows

 

[JStephen]

The could be rebar around the outside perimeter but not across the top, with bolt pattern pulling out.

 

[hokie66]

A windmill not designed for wind forces? Fancy that!

 

[CELinOttawa]

hahaha... Love the comment Hokie. I agree with all the comments - This looks like seriously low steel to no steel. Crazy!