Archive for April 2012
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One Week Until NASCC!
Posted by Tasha Weiss on April 11, 2012 at 3:44 PM.
There’s just one week until the opening of the 2012 NASCC: The Steel Conference, which takes place April 18-20 at the Gaylord Texan Convention Center in Dallas! Here are some last-minute updates and key information that you won’t want to miss as you plan your trip:
- Tomorrow is the last day to register online for the conference. After April 12, all registrations will be taken on site at the conference at increased rates. So don’t delay; register now at www.aisc.org/nascc.
- Attention students! You will have a chance to win an iPad by attending the Students Connecting with Industry Sessions (SCIS) program on Thursday (April 19). Be sure you are registered for the conference, and contact AISC’s Maria Mnookin (firstname.lastname@example.org) to register for the SCIS program. Learn more about SCIS at www.aisc.org/scis. (Note: To win the iPad, you must attend the entire SCIS program and be present for the drawing at the afternoon “Direct Connect” portion of the program.)
- A reminder for exhibitors: The on-site Exhibitor Registration desk opens Tuesday, April 17, from noon until 5 p.m., and will also be open at set times from Wednesday through Friday. You can view the registration desk hours and other key scheduling information at http://bit.ly/HLmHPK. If you have not yet received your conference materials in the mail, you can pick them up at the Exhibitor Registration desk.
- Celebrating AISC Award winners: Join us in honoring all of this year’s AISC Award winners by stopping by the AISC booth (#337). On display will be all of the significant projects and individuals that have made a difference in the success of the fabricated structural steel industry, as well as a massive library of AISC publications and interactive kiosks. The winners of this year’s AISC Awards–including individual awards, NSBA/AISC Prize Bridge Awards and AISC IDEAS2 Awards–will also be recognized during the Opening Keynote session on Wednesday, April 18, beginning at 12:30 p.m.
See you in Dallas!
Metal Challenge Contest: Share Your Works of Steel
Posted by Tasha Weiss on April 10, 2012 at 1:54 PM.
Instructables, a web-based documentation platform for users to share their creations, is offering a Metal Challenge contest for metalworkers to enter and showcase their handmade projects (including your steel sculptures, of course!).
There are three ways to enter the contest: You can upload and share one or more photos of your project; share “how-to” photos with step-by-step text instructions; or share an informative video about your project that you already have uploaded to websites, such as YouTube.
Entries will be rated by a panel of judges and the winners will receive one of nine prizes, including a Hobart MIG welding package. Multiple entries will be accepted, but each entrant can win only one prize.
You can submit your project entries and find more information at www.instructables.com/contest/metal/. The deadline for entry submissions is May 7, 2012.
And speaking of steel contests, did you know that AISC has a steel sculpture competition? Last year AISC introduced its SteelDay Sculpture Competition for full and associate members to create and display their own innovative steel sculptures. Seven were entered in the contest and posted to SteelDay’s Facebook page, where fans voted on their favorites. (You can also view all seven projects in our previous news post.) Because of the impressiveness of each sculpture and the great show of talent, all seven entries will be on display at the 2012 NASCC: The Steel Conference next week in Dallas, where the winner will be determined by conference attendees. (The sculptures will be on display near the registration area; be sure to stop by and vote!)
First U.S. Green Building Code now Available
Posted by Tasha Weiss on April 9, 2012 at 11:09 AM.
Last week the International Code Council (ICC) published the first U.S. code for green building design and performance, the International Green Construction Code (IGCC), aimed to significantly reduce energy usage and greenhouse gases in new and existing buildings.
The code, approved last November after two years of development, applies to all new and renovated commercial and residential buildings more than three stories high. It sets baseline standards for all aspects of building design and construction, including energy and water efficiency, site impacts, building waste and materials.
How does the new code differ from LEED certification? LEED is a voluntary rating system where designers can choose certain areas on which to focus, in an effort to gain the desired number of points or credits. The new IGCC, on the other hand, has established enforceable minimum requirements for every aspect of building design and construction for projects in jurisdictions that adopt it. Local and state governments have the choice of adopting the code but once they do, it’s enforceable. They can also add their own requirements that address local concerns, as well as choose whether to apply it to the entire jurisdiction or on a per-project basis.
The IGCC is available for purchase on the ICC website at http://bit.ly/Hs1L2c. For more information about the new code and an overview of its mandatory requirements, visit www.iccsafe.org (direct link: http://bit.ly/Hn5bzx).
Steel Shots: Not Your Average Tub
Posted by Tasha Weiss on April 7, 2012 at 1:51 PM.
Steel tub girders easily handled the long spans on the interchange at Interstate 30 near Dallas. Completed tub girder sections were assembled in the fabrication shop of Hirschfeld Industries, San Angelo, Texas (NSBA/AISC member and AISC Certified Fabricator), with internal diaphragms and top lateral bracing installed. Photo: Austin Bridge & Road
With the recent completion of the Eastern Extension of the President George Bush Turnpike (PGBT), the North Texas Tollway Authority (NTTA) has completed a vital link and increased mobility between outlying cities to the west and north of Dallas.
Critical to accessing this new extension is the interchange at Interstate 30, constructed by the Texas Department of Transportation (TxDOT). The interchange consists of four direct connector ramps linking the PGBT main lanes to the reconstructed I-30 main lanes. The direct connectors consist of a single-lane ramp supported primarily on pre-stressed concrete U-beams with spans varying from 80 ft to 100 ft. As the bridges cross the I-30 frontage roads and main lanes, steel superstructures are required to accommodate the longer spans and the tighter horizontal curvature they involve.
Trapezoidal steel box girders (or tub girders), with spans up to 255 ft, were chosen to match the appearance of the concrete U-beams and for their desirable aesthetics. The project has eight trapezoidal steel box girder (or tub girder) units; each unit has a unique span arrangement and horizontal curvature with a minimum radius of 890 ft.
Tub girders on horizontal curves behave fundamentally differently than curved I-girders. I-girders have very little torsional stiffness and require cross frames between the girders to redistribute torsion in the system into shears between the girders in the cross section. Tub girders, on the other hand, have significant torsional stiffness and typically are stable without the need for additional cross frames or diaphragms between the girders.
Assembling the girder sections in the fabrication shop created a very stable section that was much easier to handle than a traditional I-girder. In the field, the additional torsional stiffness of the tub girders allows them to be erected without the need for external diaphragms, which greatly reduced the time needed for erection.
You can read more about tub girders and the new Eastern Extension of the PGBT in the April issue of MSC, available now. The article provides a preview of some of what the author, Greg Kochersperger, P.E., professional associate with HDR Engineering, Dallas, will present in Session B13 at the World Steel Bridge Symposium, April 18-20 in Dallas. The final program for the 2012 WSBS and NASCC: The Steel Conference is now available at www.aisc.org/nascc.
New Jumbo HSS Now Available in the U.S.
Posted by Tasha Weiss on April 5, 2012 at 10:38 AM.
Atlas Tube, a division of JMC Steel Group (and an AISC member), announced it has partnered with Nippon Steel and Sumikin Metal Products Co., Ltd. (NSMP) and Mitsui and Co. Ltd. to supply “jumbo” hollow structural sections (HSS) to the North American market. The jumbo sizes, which were not originally available in North America, range from 18-in. square to 22-in. square and up to 0.875 in. in wall thickness. Atlas Tube will market and distribute these jumbo HSS products throughout North America. (Photo: JMC Steel Group)
Typically used in vertical column and diagonal bracing applications and as members of large, long-span trusses, the jumbo HSS sections offer an alternative to open sections and built-up, welded box sections used in structures with a high load demand.
“As an engineer, you want all the tools at your disposal to effectively solve design challenges in a cost-effective and timely manner,” says Bradlee Fletcher, a structural engineer with Atlas Tube. “Readily available jumbo HSS will be another option for engineers to do just that, especially for structures with large load demands, such as ones in high seismic areas.”
The jumbo sizes are now available from Atlas’ Chicago facility. For more information on the new sizes, visit www.atlastube.com/jumbo-hss.
The ABCs of Rapid Bridge Replacement
Posted by Tasha Weiss on April 4, 2012 at 3:36 PM.
State transportation departments looking to replace bridges using accelerated bridge construction (ABC) techniques will soon have a standardized design tool kit as a reference, according to an article published last week in Engineering News-Record.
Developed as part of the second Strategic Highway Research Program (SHRP 2) and administered by the Transportation Research Board (TRB), the tool kit contains standardized plans for modular components, erection concepts, construction specs and other data that can be applied to a wide range of projects.
According to ENR, the entire tool kit will undergo beta testing this summer in Vermont, as the state’s Agency of Transportation plans to apply a variety of ABC techniques to replace 17 bridges damaged last September by the remnants of Hurricane Irene. The kit’s sample plans for modular superstructures cover spans (up to 130 ft) using concrete-on-steel beams, concrete-bulb tees with precast decks and concrete double-T systems.
The kit’s first field demonstration took place last fall with the replacement of the U.S. Route 6 Keg Creek Bridge in Pottawattamie County, Iowa. Using ABC, the bridge was constructed with minimal impact on traffic–only a two-week road closure. (Traditional construction methods would likely have required at least partial closure of the road for several months, resulting in substantial traffic disruption.) You can read more about the Route 6 bridge replacement in NSBA’s March e-newsletter.
The full ABC tool kit article is available (with subscription) at ENR.com (direct link: http://bit.ly/HoERTM).
New and Improved Digital Steel Construction Manual
Posted by Tasha Weiss on April 3, 2012 at 3:37 PM.
When the digital edition of the latest AISC Steel Construction Manual was introduced last year, it proved to be a great alternative to carrying around the nearly 4-lb hardcover book. You could view the entire 14th Edition Manual, print out sections, copy and paste from the PDF file and search for keywords. And now it’s even better!
In response to user feedback, AISC has developed a new version of the digital Manual that offers all of the following improved features:
- The ability to load the file on more than one computer (for example, your desktop and your laptop). In all, the digital manual can be downloaded for use by one individual on up to six devices.
- The option to enable bookmarks.
- A more robust navigation tool (a table of contents).
- The ability to use it on a tablet (including the iPad and Android tablets, and Galaxy Tab 10.1).
To obtain the new digital manual, visit www.aisc.org/bookstore and purchase the digital edition of 14th Edition Steel Construction Manual. The download instructions are very specific; we recommend you read them carefully!