Hurricane Michael

[JedClampett]

I don't think I missed a thread, but if one is already started, I apologize.
I had occasion to spend a day in Panama City, FL and do limited damage evaluation (one facility) after Hurricane Michael. I am not an expert, but I did get to do the same after Hurricane Irma in the Florida Keys, so I have some comparisons. These were mostly drive-bys, so I don't have any pictures.
[ul]
[li]This was a much bigger storm in an area where Hurricane Design is not as advanced as South Florida.[/li]
[li]Metal Buildings did not fare well.[/li]
[li]Residential took the biggest hit. In general, engineered buildings, even if they weren't designed for the storm intensity, did pretty well.[/li]
[li]Gas station canopies mostly held up well, but their fascia and trim is distributed all over the county.[/li]
[li]Architectural Components were the most likely item to fail. Roofs, both metal and shingle, were in very bad shape. Doors and windows, ditto.[/li]
[li]There are hundreds, maybe thousands, of people living out of RV's. I'm not sure if they're clean up workers or residents whose houses are unlivable.[/li]
[li]Thousands of trees broke about 15 ft. up the trunk. This will be a huge clean up effort. I might say that let mother nature take care of this, but after the fires in CA, removal might be necessary.[/li]
[/ul]

 

[JAE]

Metal Buildings did not fare well.

LOL. Not surprising.



Check out Eng-Tips Forum's Policies here:
faq731-376

 

[cranky108]

Somehow metal building in the wind seem to find their way into overhead power lines. Just from what I have seen.

 

[RickyTickyTavi]

Metal Buildings did not fare well.

It seems like the entire wind code was developed for the metal building folk. Those buildings, nearly every time I've checked them, are running at 99 percent utilization for whatever code they were designed under. I generally try to warn architects everytime they want to modify one of these bad-boys that its generally not easy, and can be quite expensive.

 

[RickyTickyTavi]

Architectural Components were the most likely item to fail. Roofs, both metal and shingle, were in very bad shape. Doors and windows, ditto.

I have yet to calculate wind-loads for Components and cladding under ASCE7-16, but I have heard that the design pressures have nearly doubled in several instances for the new design code. Perhaps this will rectify some of those failure instances.

 

[charliealphabravo]

Does anyone know if this ended up being a design wind event?

 

[hokie66]

Let's not give all steel buildings a bad name because of what you folks call the PEMB crowd. Engineered and pre-engineered are not the same thing.

 

[JAE]

Hokie66
Agree.
All buildings are pre-engineered.
I prefer the term Pre-Manufactured.

Check out Eng-Tips Forum's Policies here:
faq731-376

 

[CWB1]

I believe you're confusing manufacturing method with build quality, which correlates back to risk category and other useful metrics. The obvious issue with that rabbit-hole being the question of paying less multiple times or paying more once. Personally I tend to favor the later with most things and especially buildings.

 

[hokie66]

I'm not confused, if you mean me.

 

[RickyTickyTavi]

No. You're right. I'm referring to the premanufactured buildings.

 

[Phil1934]

There was an earlier thread where someone was asking for help designing a metal bldg. foundation for wind uplift. The light-hearted answer was the building will be gone before the slab lifts. The OP said " I can't put that in my report!"

 

[CWB1]

I believe multiple folks were/are confusing manufacturing method with quality/durability. They're two independent variables. Statistically they may be associated, but failure analysis and lessons learned should only consider the case presented.

 

[hokie66]

CWB1,
We aren't confusing the manufacturing method with quality at all. We are primarily talking about design issues. In many, but not all, "PEMB" structures, there is little robustness to deal with the unexpected. But then again, you get what you pay for. It is a shame that the public does not realize that, or want to know.

 

[charliealphabravo]

For most jurisdictions the openings on PEMB structures are not well protected against wind. This means that structures designed to be Enclosed for economy (ie most of them) will likely experience Partially Enclosed conditions during a wind event. Bye bye wall and roof panels.

 

[CWB1]

We aren't confusing the manufacturing method with quality at all. We are primarily talking about design issues. In many, but not all, "PEMB" structures, there is little robustness to deal with the unexpected. But then again, you get what you pay for.

You're contradicting yourself, agreeing while disagreeing with me on the same point. Per the above, not all PEMB structures are designed to minimum quality/price/durability. IMHO the takeaway is that there are issues with the quality/price/durability level some are built to, not the particular manufacturing/construction method.

Not trying to nitpick, but I've found that there's good money in doing the odd jobs that go against common perception.

 

[hokie66]

I didn't think I was confused, but now I am. Never mind.