Archive for April 2011
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Steel Shots: All Rise
Posted by Tom Klemens on April 15, 2011 at 9:09 AM.
Sunrise over Chicago’s North Lake Shore Drive Bridge, the first of 18 movable bridges that cross the Chicago River in the two-mile stretch beginning at Lake Michigan. (They’re all steel bridges, by the way.) From mid-April until early fall the city coordinates a lift schedule with local boat storage yards to minimize the disruption to surface traffic in the city caused by raising the bridges. Photos: Robert Johnson (sunrise), James Phillips (raised bridge).
Well, spring has come to Chicago, and there’s no more sure sign than that the Chicago Department of Transportation has posted its Spring 2011 Bridge Lift Schedule. Every Wednesday and Saturday beginning tomorrow, April 16, the city will raise the bridges in sequence along the river to allow primarily sailboats to make their way from storage yards out to Lake Michigan and back.
Although the bridges also are raised at other times, a coordinated schedule with boat storage yards helps keep the impact on downtown surface traffic to a minimum. To learn more about the spring bridge lift season, including a link to the schedule, visit the City of Chicago website by clicking here.
For some interesting background and insight into Chicago’s movable bridges, take a look at “Two Miles - Eighteen Bridges: A Walk Along the Chicago River, ” by James S. Phillips. A native of New Mexico, Phillips split his engineering career between private industry and teaching math and engineering courses at the community college level. He is currently on sabbatical in Chicago where he continues to gather information on bascule bridges in Chicago’s Loop and also leads tours. His 172-page book, published online in 2008, is available at www.chicagoloopbridges.com and provides both an historical context for these wonderful and diverse structures as well as technical insight into how they work. The included photos and maps make this a good guide for a Chicago outing (or two). For just $3.75, the book can be read online, through Scribd, or downloaded as a PDF file. It also is available in a format for mobile devices. You can learn more by visiting Phillips’ Chicago Loop Bridges Facebook page, accessible by clicking here.
And when you plan your Chicago River bridge tour this summer, make sure to include the McCormick Bridgehouse & Chicago River Museum, which opens with a preview this year on May 14, Chicago River Day. Throughout the summer you can observe the bridge’s inner workings up close in the river-level gear room or from the top of the bridge tower. Visit www.bridgehousemuseum.org for details or to make reservations. And welcome to summer in Chicago!
Two-Span UDOT Bridge Rolled into Place Overnight
Posted by Tasha Weiss on April 14, 2011 at 9:13 AM.
The Utah Department of Transportation and contractor Provo River Constructors (PRC) made history overnight on March 26-27 with the successful move of the Sam White Bridge over Interstate 15 in American Fork, Utah. Working with the longest two-span bridge ever moved by Self-Propelled Modular Transporters (SPMTs) in the Western Hemisphere, crews set the new bridge into place at approximately 4 a.m. on March 27 and reopened the freeway at 7 a.m., three hours ahead of schedule. The move was part of UDOT’s $1.725 billion Utah County I-15 Corridor Expansion (I-15 CORE) freeway reconstruction project.
PRC, the consortium of expert local, regional and national contractors and engineers acting as the project’s design-build contractor, constructed the 354-ft, 1,900-ton structure on falsework in a “bridge farm” along the east side of I-15. A steel-plate girder design was chosen for the Sam White Bridge due to its relatively light weight and its ability to follow the profile grade line. AISC / NSBA member Utah Pacific Bridge & Steel Corporation, Lindon, Utah, fabricated the steel for the bridge, which was designed by the Moon Township, Pa.-based Michael Baker Jr., a member of the PRC consortium.
Moving the bridge perched 21 ft in the air involved precise coordination. The two-span structure was raised off the falsework, then moved simultaneously using four lines of SPMTs, which are hydraulic jacks on wheels, controlled by a single joystick.
After raising the structure off its falsework, crews moved the bridge approximately 500 ft across eight freeway lanes—which included rotating it to the crossing’s final 48-degree skew—and lowered into place. To see a two-minute preview and animated simulation of the move sequence, go to http://bit.ly/euZizx. UDOT’s five-minute time lapse video of the actual move is also available at http://bit.ly/eAvSaP.
Located 30 miles south of Salt Lake City, the Sam White Bridge is one of 59 new, modified or rebuilt structures on the 24-mile Interstate reconstruction project. The state-funded project is reconstructing the highway from Lehi to Spanish Fork which connects the northern and southern halves of the state. The I-15 CORE project is scheduled for completion by December 2012. To learn more about the bridge-related aspects of the project, visit http://bit.ly/fcHc8c.
Engineering Journal Q4 Now Online
Posted by Tasha Weiss on April 13, 2011 at 9:03 AM.
AISC members are reminded that the Fourth Quarter 2010 issue of Engineering Journal is now available to AISC members online in digital edition format. Members can view, print, and share the current issue online by clicking here.
Papers in Engineering Journal Q4 include:
* Prediction of Bolted Connection Capacity for Block Shear Failures Along Atypical Paths by Qing Cai and Robert G. Driver
* Seismic Demand on Column Splices in Steel Moment Frames by Jay Shen, Thomas A. Sabol, Bulent Akbas, and Narathip Sutchiewcharn
* A Discussion on Critical Evaluation of Equivalent Moment Factor Procedures for Laterally Unsupported Beams by Steven Wilkerson
This issue also features a special focus on non-building structures.
Article searches for the complete collection of Engineering Journal remain available at www.aisc.org/ej. Downloads of current and past articles in PDF format are free to AISC members and ePubs subscribers. Non-AISC members may subscribe to Engineering Journal at AISC’s website here.
This issue marks the one-year anniversary of Engineering Journal digital editions. Feel free to e-mail the Editor of Engineering Journal, Keith Grubb, P.E., S.E., with comments and questions at firstname.lastname@example.org.
Nucor Steel Challenge Engages Future Engineers
Posted by Tasha Weiss on April 12, 2011 at 8:59 AM.
Nucor Corporation is inviting budding engineers ages 12-18 who live in Alabama, Arkansas, Indiana, Nebraska, North Carolina, South Carolina, Texas, or Utah to team up and create steel innovations for the first ever Strength of Steel Challenge. The contest encourages youth to delve into the many everyday uses of steel and design their own steel structure for the home, school, or car. The invention must showcase the strength of steel by holding a minimum of five pounds and include recycled steel. Along the way, Nucor takes contestants through the learning process of what’s involved in a steel project and the various roles and responsibilities of the project team. Teams can even email a Nucor engineer with questions about designing their structure. Visit the Strength of Steel Challenge website at www.strengthofsteelchallenge.com to learn more.
Entries must be submitted by teams consisting of 2-4 members and may be submitted online at www.strengthofsteelchallenge.com/content
/how-enter or by mail by 5 p.m. on Tuesday, May 3. To view all entry requirements, visit the Strength of Steel Challenge website at www.strengthofsteelchallenge.com/content
All semifinalists will receive a two-day/one-night trip for each team member and one parent/guardian each to Charlotte, N.C., to attend the final judging event.
The winning team will receive:
* The Nucor Future Engineer National Champion award
* $3,000 for the team
* A brainstorming session with an engineer from a Nucor mill
Prizes will also be given to semifinalist teams, and the winning team will also have the opportunity to nominate their most inspirational teacher for an award. Learn more about the prizes available at www.strengthofsteelchallenge.com/content
Key Registration Information for NASCC: The Steel Conference
Posted by Tasha Weiss on April 11, 2011 at 9:06 AM.
If you haven’t already, mark May 11-14 as “at NASCC: The Steel Conference in Pittsburgh” and join the more than 3,500 other steel construction industry professionals expected to attend. Here are some important deadlines and tidbits to keep in mind to register for the conference and plan your trip to the Steel City.
- April 18 is the deadline to book your hotel room at one of the official NASCC hotels in Pittsburgh before the blocks are released, and reservations will then be based on availability at higher rates. Reserve a hotel room at www.aisc.org/nascc. It’s also the date to register by in order to receive your name badge and registration materials in the mail prior to the conference. Check your mailboxes the week of May 2 for these materials.
- NASCC 2011 pre-registration discounts are available through May 5. After that date, on-site registration rates apply. Full pre-registration for AISC members is $390 (and the third registrant from your firm gets a discounted rate of $195). Full pre-registration for non-AISC members is $550 (and the third registrant from your firm gets a discounted rate of $285). Your registration gains you admittance to the more than 90 technical sessions at the conference, keynote address, the T.R. Higgins Lecture, and the exhibition hall (featuring the latest products ranging from structural software to machinery for cutting steel beams). For convenient online registration, go to www.aisc.org/nascc.
- The website also offers program information to help you plan to get the most out of the technical seminars, networking, and product showcase. Select “Schedule” for an overall timetable for the week’s events as well as links to downloadable PDF files of the NASCC Schedule-At-A-Glance and the NASCC Final Program.
Don’t miss out on this once-a-year opportunity to learn the latest techniques, see the most innovative products, and network with your peers and clients. And, don’t forget about those PDHs (Professional Development Hours); you can earn up to 28 of them at The Conference. Visit the NASCC website at www.aisc.org/nascc for the most thorough information about the conference.
For late-breaking news about The Conference, you can listen to an NASCC interview with AISC Vice President Scott Melnick. Click on the podcast button to the right or visit www.aisc.org/podcasts.
Steel Shots: Cherry Blossom Beauty
Posted by Tasha Weiss on April 8, 2011 at 9:20 AM.
The Cherry Blossom Palace’s shell is a three-dimensional structure made of slender interwoven steel components that form rhomboids, triangles, and pentagons, which make it behave like a dome. Its cladding is a continuous three-layer membrane which adapts to the initial geometry using differently sized tessellates, and the dome surface features seven drilled holes for the entrance of visitors, light, and views of the valley landscape. Click on the photo for a view from inside the shell. Photos: AMID.cero9 Cristina Diaz Moreno + Efren Garcia Grinda
It’s cherry blossom season, the two-week time period in early spring when cherry trees reach their peak blooming season and clouds of pink and white can be seen all over Washington D.C., among other places. More than a million people visit the city for the annual National Cherry Blossom Festival, which started on March 26 this year and runs through the end of this weekend.
Cherry tree blossoms are traditionally celebrated all over world, and a similar large local festivity in the Jerte Valley, Spain is what inspired a Spanish team of architects, AMID.cero9, to design the Cherry Blossom Palace structure. Blending in with its surroundings of cherry blossom trees in the valley, the flower-like dome structure was designed to highlight the intense bond with the landscape through its presence, position, volume, and material.
The Cherry Blossom Palace project won a 2010 CIDECT Award at last December’s International Symposium on Tubular Structures in Hong Kong, China. Xavier Aguilo I. Aran, from the University of Barcelona, Spain, took first place for the Design Award for his paper on the Cherry Blossom Palace project, which he was involved in as a structural consultant. You can download the paper from CIDECT’s website at http://bit.ly/fJhEWT, and view our previous Steel in the News post here for more information about the awards.
Deadline Approaches for Fabricators to Contact EPA
Posted by Tasha Weiss on April 7, 2011 at 9:29 AM.
An article in the April issue of MSC provides important information for structural steel fabricators about a pending EPA deadline. In “Clean Air Regulations Coming to Your Fabrication Shop,” AISC director of research Thomas J. Schlafly explains some of the nuances of the National Emission Standards for Hazardous Air Pollutants, 40 CFR Part 63, and how they affect fabricators. This is especially applicable to those shops not previously covered as “major emitters of hazardous air pollutants.”
Bottom line: Chances are that you need to submit an Initial Notification of compliance to the EPA by July 25, 2011. To read Schlafly’s explanation and learn about additional resources, click here or go to www.modernsteel.com/backissues.
Photo Contest for Huey P. Long’s Last Big Lift
Posted by Tasha Weiss on April 6, 2011 at 9:29 AM.
Calling all Huey P. shutterbugs! To commemorate the third and last bridge segment lift of the Huey P. Long Bridge Widening Project, in New Orleans, the Louisiana Department of Transportation and Development (DOTD) and Louisiana TIMED Managers (LTM) have launched an online photo contest for the public to showcase their shots of the memorable last lift scheduled for this Saturday — view live camera images of the lift starting at 5 a.m. Photo entries are due by Friday, April 15. For thorough information on how to enter the photo contest, visit LTM’s bridge project website here.
If you don’t have a chance to visit the Huey P. Bridge, you can still participate in the photo contest’s People’s Choice Award by voting for your favorite photo after next Friday. Submitted photos will be available on the Huey P. Long Bridge Widening Project Facebook page or at www.yogile.com/hueypbridge, for those without Facebook access.
The Huey P. Long Bridge, a cantilevered steel truss bridge, was opened to traffic in 1935 and has served the New Orleans area residents and visitors for almost 75 years. The widening of the bridge is being accomplished by adding new trusses to each side of the bridge - providing a safer, more reliable Mississippi River crossing. This four-phase project began in April 2006, and the entire project will be complete in 2013. Check out time-lapse videos of the first two big lifts at www.timedla.com/bridge/long/activity/.
For background about the innovative erection plan devised to erect the widening trusses span by span, as well as photos highlighting the project’s first and second lift, read the September 2010 article in MSC. More information about the project can also be found by checking out our previous Steel Shots post from last July 2.
AISC, SSPC Standard for Paint Shop Certification Available
Posted by Tasha Weiss on April 5, 2011 at 9:59 AM.
AISC and SSPC have developed a joint certification standard for shop application of protective coatings. The standard, “Certification Standard for Shop Application of Complex Protective Coating Systems,” aka AISC 420-10/SSPC-QP 3, describes requirements for certification of firms that apply complex painting systems.
The new standard is the culmination of several years of work by a joint committee of coatings and steel industry professionals representing both organizations. It’s available now for free download on AISC’s website at www.aisc.org/JointPaintStandard and SSPC’s website at www.sspc.org/market-place, for inclusion into project specifications and contract documents.
For more information go to AISC’s press release here.
Posted by Ted Sheppard on April 4, 2011 at 2:22 PM.
Years ago when I was with Tri State Steel Construction, we had a big girder job in Cleveland. Some of the girders were deeper than the ones we had been dealing with on other projects. I was at the site when we erected the first girder, and, as usual, we braced it against rotation at the bearings.
The brace was a single angle from the top flange down to the pier top. We had used the same size angle we always used, but longer. Looking at it in person, it looked very flimsy. I went back to the office and calculated the L/r ratio. It was 244. When I was with Bethlehem Steel, we were told to give no compressive value to members whose L/r ratio was 250 or higher. In this case, we were almost using a wet noodle as a brace.
That’s when I also realized that I had never established a design standard for these braces, or for the braces between girders used to stabilize subsequent erected steel.
We made the correction in the field, then set the limit for the end bearing bracing so that L/r would never be higher than 180. The intermediate braces could not have an L/r greater than 200.
The lesson here is that if you have no standards, you can get into trouble. Others may not like the limits that we chose, and that is fine. Everything worked with these limits, and that is what matters.
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