Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Register Log in
  • Congratulations The Obturator on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Dallas Cowboys indoor practice facility collapses

Status
Not open for further replies.
bnickeson

bnickeson

Structural
Apr 7, 2009
87
Cowboys' indoor facility collapses during practice
3:38 PM Sat, May 02, 2009 | Permalink | Yahoo! Buzz
Tim MacMahon E-mail News tips


The afternoon practice ended in horrifying fashion when the Cowboys' indoor facility collapsed.

While a violent thunderstorm pounded rain down on the roof, the lights started shaking back and forth. Then chaos broke out, as the facility collapsed and players, coaches, reporters and team personnel scrambled for safety.

Several people were trapped under the wreckage. Police and emergency personnel have arrived on the scene.

More to come.

UPDATE: According to a Cowboys spokesman, at least four members of the team's support staff are being taken to the hospital. All players and coaches are believed to be safe. Rescue personnel is still searching through the debris.


Cowboys coach Wade Phillips said that DeCamillis sustained a neck inury, was stabilized and taken to an area by ambulance.

"He was moving his hands and he was talking," Phillips said before leaving for the hospital.

Phillips said a couple of players suffered minor injuries.




Video of the collapse is here:

 
The same thing happened to the football bubble at Arizona State University last August. High winds, but nothing beyond code requirements.
My question is: Don't these structures need to be designed for a 90 mph wind?
 
Another one collapsed a few years ago in New Jersey. Used by New York Giants football team. I think that collapse was attributed to unbalanced snow loading. Maybe these teams should go back to practicing outdoors, better for their health.
 
Consider there are so many millionaires in the facility, whom in turn bring in multiple of millions every year to the owner, he shall do better.
 
FYI- This is not an air-supported structure. Collapses of air supported structures are not unusual. This is a fully engineered structural steel framed, tension fabric structure. Collapses of this type of structure are extremely rare. This structure was designed to a minimum 90 mph exposure C wind condition and stamped by a Texas licensed PE. The company that built this, and the engineer who stamped it, have been involved in litigation due to another collapse. I have been in the industry 10+ years, and these are the only two collapses I know of.
 
They (ROE & contractor) certainly now how to keep themselves busy: design-build-collapse-court-design-build-collapse...... Where is the state regulatory & PE board?
 
The first collapse was in a different state and the liability was a little murky. Hopefully the state reg will get involved here.

On the first collapse, there were some ancillary systems not installed properly (sprinklers) that allowed the manufacturer to duck complete liability. Plus there were no injuries.

This will probably sink them, though. Assuming the winds were well within the structural ratings, liability should be clear. And with injuries and the high profile of the incident, I don't see them surviving.
 
Tentguy,

Do you know of the EOR personally? It sounds like there may be a track record of cutting corners?
 
Just watched on late night news. What was the support material? Some looks like have completely broken down to seperate pieces.
 
Here’s some relevant excerpts. I’ve deleted most of the names. [red](My comments in red) [/red]

On October 30, 2002, Summit/Cover-All released the
drawings and calculations to Mr. {}, and Mr. {} reviewed
them prior to his sealing them the next day on
November 1, 2002. [red] Doesn’t this tell you something
right off? The EOR seals the whole structure after only
one day! [/red]

On November 1,2002, Mr. {} signed and sealed …[the]
drawings for the warehouse at Tioga.

On November 1, 2002, Mr. {} signed and sealed [the]
calculations for the design for the warehouse.

Prior to signing and sealing them, Mr. {} reviewed the
drawings and calculations to see if they matched his
general experience with [ ] buildings. He did not do any
independent calculations for [ ]. [red] Now you don’t
necessarily have to do independent calculations, but I
wonder how many calcs were actually looked at? Might be
interesting to know. [/red]

A fax, dated November 5,2002 from [ ] to Carusone,
identified that Mr. {} would serve as the engineer of
record for the building; that Mr. {} would be responsible
for the inspection of the building; and that he would
certify that it was designed in accordance with the
Philadelphia Building Code.

Mr. {} did not review the Philadelphia Building Code for
this project. Instead, Mr. {} assumed that [ ]'s design
and calculations were correct and had been checked in
accordance with the Code. He relied on that assumption in
drafting the November 18, 2002 letter.
[red]If the Philly code was unique, it might have affected
the design…I don’t know if it has any special snow load provisions unique to that area[/red]

On December 30, 2002, {} signed and sealed a Special
Inspection and Final Compliance letter to L&I stating that
he had provided special inspections of the [ ] warehouse,
including its "superstructure, bolts and nuts, welding,
structural steel and bracing, foundations, footers, and
anchor bolts."

Mr. {} conducted a walk through of the [ ] warehouse
prior to completing the Special Inspection and Final
Compliance letter.

The Special Inspection letter also stated that Mr.
{}’s “professional opinion and in accordance with the
accepted standards of my profession, the building has been
constructed in compliance with the provisions of section
1308 0 of the 1990 BOCA. National Building Code". However,
Mr. {} admitted that he did not examine the 1990 BOCA. Code
prior to signing the Special Inspection.

[red]Now the outside SE comes in and describes what happened. [/red]
The reason for the structural collapse was a failure of
the design to use the appropriate values in calculating
the snow load on the roof of the buildings. This collapse
was also related to the use of eccentric Bange connections
in the truss structure and the failure to use a sufficient
number of web members in the fabrication and erection of
the trusses.

One design flaw related to the snow load which the
structure could accommodate. If the building had been
designed according to the specifications called for in the
Contract which were in accordance with ASCE 7~93, the
structure would have been able to carry a load of 63
pounds per sq. ft. The actual design was calculated to carry 35 pounds per sq ft.
[red]Quite a big difference[/red]

One of the key factors in the under design was the failure
to properly account for the accumulation of snow in the
valley between the buildings which would produce an
unbalanced snow load or an uneven distribution of the
weight of the snow.

The other design flaw was in the eccentric flanges or
splices in the truss member. As shown above, the flange
attachments covered 2700 of the diameter of the truss end.
This proprietary design was utilized to accommodate the "C-
Clip" on top of the truss which was used to hold the outer
building fabric as an integral building structure (also
discussed above).

Because the flange did not have a connection over3600 of
the diameter of the pipe section, it was proportionately
weaker. The evidence supported the opinion that the
unconnected 90° section was a failure point of the truss
section.

The witness opined that in the landward building that
collapsed, there were catastrophic failures of the
eccentric splice on the top cord of the truss at the
ridgeline or high point of that building.

The third contributing cause of the building collapse was
the failure to install the required number of load bearing
members known as king pins. King pins are vertical struts
intended to be placed between the top and bottom cord of
the trusses. It was a load bearing member.

The evidence demonstrated that in each of the trusses, the
vertical king pins were missing at two (2) locations.
These locations corresponded to the locations of the
splices of the truss where the eccentric flange sites were.
Although the design called for king pins at certain splice
locations, the construction failed to incorporate one
hundred twenty-four (124) such king pins which were to be
located at the splice connections.

Although not every splice failed, the splices that did
fail were at locations where king pins were included in
the design but were not installed. It appears that half
of the missing king pins were designed into the truss
but not installed. This is demonstrated on Page 3 of P-10
which is a signed and sealed, "as built" drawing.
[red]Missing king pins….oops[/red]
 
These are excerpts from the Philadelphia collapse...not the Dallas collapse...I meant to say that up front.

sorry.
 
tentguy,

The court in Philadelphia assessed 88% of causal damages to Summit, and the remaining 12% to the Pensylvania engineer who certified the structure. So it doesn't look like they ducked liability, unless you know otherwise.
 
hokie66

I should have been more clear-

I didn't mean to imply that legally they ducked liability- they took it pretty square on the chin. I only meant to suggest that on a commercial level, they were able to use some of the arguments they presented to the court (specifically those concerning the improper installation of the sprinkler system) more successfully in convincing future clients that they got the raw end of the deal, and that they managed to stay in business and win new contracts.
 
One of the theories of the Dallas collapse was wind shear.One of the news programs showed a rare photo of wind shear.It looks like an up side down tornado.A column of cold air falls downward at speeds up to 70 mph .this widens as it approaches the ground speeding up to as much as 100 mph.
 
Even in a wind shear event with winds in excess of the building ratings, the frame should have survived intact. The fabric would typically separate from the frames allowing the wind to pass freely. If anyone remembers the tornado that touched down in Salt Lake City several years ago, there were several shots on television showing large sheets of fabric circling in the tornado. Those were roof panels from several different fabric structures in the city. All of the frames from those structures survived intact.
 
I believe I heard a loud pop sound prior to the collapse. And I guess localized pressure had caused the beam/post (made of stainless stl? glav steel? , aluminum?) to buckle.
Also, the covering fabric seemd to make the case worse. The scene on TV was to short to make sure though.
 
Never in the business designing flag pole, this event has me started to wonder: as the pole getting taller and taller, and the size of flag is increasingly made bigger, has the effects of wind on flag been accounted for, and how? Just curious.
 
Yes it has...ANSI/NAAMM FP 1001-97. Guide Specifications for Design of Metal Flagpoles covers it.
 
WillsV: Thanks.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top Bottom