Featured Research

from universities, journals, and other organizations

NIST releases final report on Cowboys facility collapse

Date:
January 26, 2010
Source:
National Institute of Standards and Technology (NIST)
Summary:
NIST has released its final report on the May 2, 2009, collapse during a severe thunderstorm of the fabric-covered, steel frame practice facility owned by the National Football League's Dallas Cowboys.

The National Institute of Standards and Technology (NIST) has released its final report on the May 2, 2009, collapse during a severe thunderstorm of the fabric-covered, steel frame practice facility owned by the National Football League's Dallas Cowboys.

Related Articles


The final report is strengthened by clarifications and supplemental text based on comments provided by organizations and individuals in response to the draft report on the collapse, released for public comment on Oct. 6, 2009. The revisions did not alter the study team's main finding: the structure collapsed under wind loads significantly less than those required under applicable design standards.

Also left unchanged after the comment period is NIST's recommendation that other fabric-covered frame structures be evaluated to ensure adequate performance under design wind loads. These evaluations, says NIST, should determine whether or not the fabric covering provides lateral bracing for structural frames considering its susceptibility for tearing; whether the building should be considered partially enclosed or fully enclosed based on the openings that may be present around the building's perimeter; and whether the failure of one or a few frame members may propagate, leading to a partial or total collapse of the structure.

The Cowboys facility was designed as a series of identical, tubular steel frames with a tensioned fabric covering. Assumptions and approaches used in the design of the building resulted in significant differences between the original calculated wind load demands and structural capacities compared to those derived by NIST. For instance, the NIST calculated internal wind pressure due to the presence of vents and multiple doors based on classifying the building as "partially enclosed" rather than "fully enclosed" as stated in the design documents. Also, NIST did not rely on the building's fabric to provide lateral bracing (additional perpendicular support) to the frames in contrast to what was stated in the design documents. Finally, NIST included the effects of localized bending in calculating the expected wind resistance of the structure, whereas the design documents did not indicate that such bending was taken into account.

Based on data acquired during a reconnaissance of the collapsed facility, NIST developed a two-dimensional computer model of a typical structural frame and then analyzed that frame to study its performance under various wind conditions. NIST worked with the National Oceanic and Atmospheric Administration's (NOAA) National Severe Storms Laboratory to estimate the wind conditions at the time of collapse. The researchers determined that, at the time of collapse, the wind was blowing perpendicular to the long side of the building. Maximum wind speed gusts at the time of collapse were estimated to be in the range of 55 to 65 miles per hour -- well below the design wind speed of 90 miles per hour as specified in the national standard for wind loads.

NIST and NOAA analyzed the available wind data and concluded that a microburst (a small, intense downdraft which results in a localized area of strong winds) was centered about one mile southwest of the structure at the time of collapse. The wind field in the vicinity of the structure was predominately lateral, as assumed in design.

NIST is working with various public and private groups toward implementing changes to practice, standards, and building codes based on the findings from this study.

The complete text of the final report may be accessed at www.bfrl.nist.gov/investigations/investigations.htm.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology (NIST). Note: Materials may be edited for content and length.


Cite This Page:

National Institute of Standards and Technology (NIST). "NIST releases final report on Cowboys facility collapse." ScienceDaily. ScienceDaily, 26 January 2010. <www.sciencedaily.com/releases/2010/01/100126175927.htm>.
National Institute of Standards and Technology (NIST). (2010, January 26). NIST releases final report on Cowboys facility collapse. ScienceDaily. Retrieved November 21, 2014 from www.sciencedaily.com/releases/2010/01/100126175927.htm
National Institute of Standards and Technology (NIST). "NIST releases final report on Cowboys facility collapse." ScienceDaily. www.sciencedaily.com/releases/2010/01/100126175927.htm (accessed November 21, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, November 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

AFP (Nov. 21, 2014) Toyota presented its hydrogen fuel-cell compact car called "Mirai" to US consumers at the Los Angeles auto show. The car should go on sale in 2015 for around $60.000. It combines stored hydrogen with oxygen to generate its own power. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Google Announces Improvements To Balloon-Borne Wi-Fi Project

Google Announces Improvements To Balloon-Borne Wi-Fi Project

Newsy (Nov. 21, 2014) In a blog post, Google said its balloons have traveled 3 million kilometers since the start of Project Loon. Video provided by Newsy
Powered by NewsLook.com
NSA Director: China Can Damage US Power Grid

NSA Director: China Can Damage US Power Grid

AP (Nov. 20, 2014) China and "one or two" other countries are capable of mounting cyberattacks that would shut down the electric grid and other critical systems in parts of the United States, according to Adm. Michael Rogers, director of the National Security Agency and hea Video provided by AP
Powered by NewsLook.com
Latest Minivan Crash Tests Aren't Pretty

Latest Minivan Crash Tests Aren't Pretty

Newsy (Nov. 20, 2014) Five minivans were put to the test in head-on crash simulations by the Insurance Institute for Highway Safety. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins