You're welcome for that as well.

Try using 2x the cantilever length for L in the span/deflection ratio.

Also the engineering company that made the structural drawings and calculations are a local phone call for Magnum. Suggest a telecon tomorrow with a report to all anxious forum readers.

Um, not so on your ratio, unless you want to go for 480 in the bottom.

My questions stand. Already documented here. I will transmit them via various forms of mail.

Forgot, thanks to Fitch. Good info.

You can tell by looking at it that its not safe. We should have torn the damn thing down and built a new one. Stupid decision. Hopefully they fix it before it collapses

That's way exaggerated AP.

Fitch, are you saying that the top chord of the truss extends past the horizontal bottom chord at the outboard end by about 13' horizontal?

If I read you correctly, yes that's what I'm saying.

There's an additional 13' horizontal and about 5' of drop to the outboard point beyond the connection of the horizontal bottom chord and the seating raker, which would be the top chord in your description.

FTR, I had to look up those terms. I'm a business major, but I keep up with this type of stuff.

You really do, Fitch. I remember that configuration now from the construction cams. That correlates with increased flexibility, and, therefore, increased deflection, The first 4 or 5 rows were really moving.

The bottom chord elevation may very well have been set by ceiling height for the concourse below.

quote:

---

...I do think that if this is going to be a recurring point of discomfort it would behove the administrators to give these concerns a second look and make a public assurance.

---

Excellent executive summary of the discussion.

Structural engineering firm was Walter P. Moore. They do have quite a bit of stadium design experience (Minute Maid, Reliant/NRG Stadium, AT&T Stadium, etc.).

VDD

quote:

---

Structural engineering firm was Walter P. Moore. They do have quite a bit of stadium design experience (Minute Maid, Reliant/NRG Stadium, AT&T Stadium, etc.).

---

That's a pretty solid firm. I've worked with them on several big projects. That isn't to say they couldn't have made a mistake somewhere or failed to factor in all this new age new army dancing hip hop bouncing crap, but they're a good and highly reputable company.

Anyone in Texas claiming to be a structural engineer should know that WPM was the EOR for the Kyle Field expansion.

Having direct knowledge of the actual deflection limits, the ICC 300 Standard for Bleachers, and how to evaluate deflection criteria ... may be outside of some structural engineers expertise.

Also, I doubt the deflection estimates based on visual observation.

I'm lost. Is this the nerdery or something?

I'm a former President of the Galaxy and I'm also concerned.

Here are my credentials for all you doubters.

So what you're saying is don't sit in or below the south end zone of an exciting game?

That I can do!

Thanks for playing...

quote:

---

I'm lost. Is this the nerdery or something?

---

Dang I knew I should have paid attention in class. Wait, I was a ECON Major.

I started out as a structural guy but all these big words made my head hurt so I stuck with general Civil. Poop is a lot easier to understand. "Dilution is the solution to pollution".....all I needed to know.

I could see some junior engineer applying textbook live and dead loads and calling it good, but someone should be checking that. Also, didn't the Hyatt failure involve a change order on the hangers that wasn't properly evaluated?

Deflection limits are pretty straight forward, although can involve some engineering judgement since primarily based on serviceability or occupant comfort.

However, dynamic loading to be considered in determining actual deflection for comparison to limits is not clear cut in ICC 300 or the IBC (ICC 303 requires design to be in accordance with the building code). The building code contains verbiage such as "provisions shall be made in the structural design for uses and loads that involve unusual vibration and impact forces". Pretty ambiguous. Therefore the loading to determine deflections involves engineering judgement, unless there is some prescriptive dynamic loading for stadiums that I am unaware of.

The crux question is this: was the south end steel structure analyzed for vertical dynamic loading of fans jumping in unison to music such as Sandstorm (approximately 2.3 cycles per second)?

If it was and the deflection and stresses were within allowables, then we are good.

Human perception of movement can often over estimate actual movement, but I will say it was at a level that was concerning to me and the people sitting in section 245. The movement appeared to be greatest at the edge of the section to our right, 244.

Would have loved to see Magnum sit there with a stopwatch listening to sandstorm and measuring cycles

My proposal would be to stop playing ****ty music.

Texas PE here and will be sitting in the first few rows of 2nd Dec SEZ next year...I support this thread and would appreciate some response from WPM stating they have reviewed the design based on field observations.

quote:

---

i. For cantilever members, l shall be taken as twice the length of the cantilever.

---

quote:

---

Live load deflection of structural members shall be limited to 1/200 of the span.

---

And yes the dynamics should be evaluated.

we have season tickets in SEZ 2nd deck as well, and we have felt it for multiple games this year. It didn't start during Sandstorm. Any time people got hopping around on that thing, the 2nd deck started bouncing.

Whether or not it's a potential problem or not can be left answered by people who are professionals in that field, but I'm definitely going to be inquiring about this and waiting on an answer, considering our 2015 and beyond tickets are SEZ 2nd deck.

quote:

---

Everyone is a fatass!!!

---

ICC 300 does state that deflection limit is L/200. It also states that design should comply with the building code. Some of the building code limits on deflection are more stringent. Nevertheless, the deflection limits are set primarily based on serviceability or occupant comfort. I personally would use no less than L/360, which converts to L/180 if L is the cantilever length. Some code excerpts state that for floors with a span greater than about 20 feet, a more restrictive requirement than L/360 may need to be considered to avoid bouncy floors. I can assure you that a large number of folks in 245 were not comfortable.

The above comments beg the question of loading. Dynamic loading is not specified as far as I know. The reality of the dynamic load actually occurring has been discussed at length herein. It should be investigated if it has not already. I would hope than an investigation is already underway, based on reported earlier posts on this subject, of which I was unaware. The loading should be considered to be steady state IMO, as it can continue long enough to have essentially steady state results. Nowhere near all the fans were jumping. At a big SEC game where we (hopefully soon) are playing very well, the level of excitement will probably be greater.

No jumping allowed would also work. Party poopers.

Pretty sure fatass should be 2 woids.

BTW, I did not use a stop watch. I estimated 2 cycles per second. A poster was kind enough to inform us that the song is 136 beats per minute, which is 2.3 cps. Not far off.

quote:

---

BTW, I did not use a stop watch. I estimated 2 cycles per second. A poster was kind enough to inform us that the song is 136 beats per minute, which is 2.3 cps. Not far off.

---

Fair enough

ML: I support this thread and everything you're doing here. Keep up the good work.

Carl Hungus: looks like from your incessant berating of everything on this thread, as well as your status of "contractor" in your personal profile, that you either a)worked on Kyle Field or b)are closely associated with someone who did. Would you care to enlighten us?

These are the relevent photos I could find of the area from the McGiblets/Fitch construction photo page. Should help facilitate discussion. Before actually running through the calcs, I can see how the first 6 rows could see some major bouncing and have an amplified effect from being hung out so far from the column.

This can easily be fixed. I have dealt with a high rise problem like this in downtown Houston and stiffeners and mass need to be added if this is the problem. I would have expected that the engineers and constructors would have installed transducers to monitor and document the various conditions to assure the analysis was accurate and yielded the intended results.