Archive for September 2011
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Steel Shots: A Michigan Sunset
Posted by Tom Klemens on September 30, 2011 at 11:40 AM.
A portion of the Mackinac Bridge, which connects Michigan’s upper and lower peninsulas where Lake Huron meets Lake Michigan. This photo represents part of the human experience of steel as its larger than life structure crosses two adjoining bodies of water that, of themselves, are also massive on a seemingly unattainable scale. The person standing at the edge of the water looking out at the bridge provides a visual scale for a comparison of how we, as humans, use steel to achieve greatness beyond ourselves. Photo and description by Krystal Brun.
The winning photo in the 2011 AISC Student Photo Contest was taken by Krystal Brun, a senior civil engineering student at George Washington University, Washington, D.C. Brun captured this sunset at the south end of the Mackinac Bridge over the Memorial Day weekend in 2010, the night before joining the other 596 runners in the 7th annual Mackinaw Memorial Bridge Race on May 29.
The third longest suspension bridge in the world, the 5-mile-long Mackinac Bridge officially opened on November 1, 1957, and has played host to pedestrian events since the beginning. This year September 5 marked the 54th annual Mackinac Bridge Walk. The event is held each year over the Labor Day weekend and attracts thousands of participants.
The Memorial Day Bridge Race over the Mackinac Bridge was initiated in 2004, and 2009 saw the launch of the Fall Colors Bridge Race. (Also in 2009, ASCE named the bridge a National Historic Civil Engineering Landmark.) Organized by the Mackinaw Area Visitors Bureau, Mackinaw City, Mich., both races have become annual events despite the fact that runners face a steady incline with a slope of 5 degrees for the first half of the 5.6-mile course.
The 3rd Annual Fall Colors Bridge Race is scheduled for Saturday, October 8. Unlike the Memorial Bridge Race, which goes from south to north, the Fall Colors Race begins at the north end of the bridge. Click here for registration information. The Mackinac Bridge webcams should offer a glimpse of the race, which begins at 7:30 a.m. Eastern time.
Engineering Journal Q3 Now Online
Posted by Tasha Weiss on September 29, 2011 at 9:28 AM.
The Third Quarter 2011 issue of Engineering Journal is now available online in digital edition format. View the current issue online at www.aisc.org/ej.
Papers in Engineering Journal Q3 include:
- “Hybrid Moment-Resisting Steel Frames,” by Finley A. Charney and Ozgur Atlayan.
- “Lightly Damped Moment-Resisting Steel Frames: A Design-Based Approach,” by Ozgur Atlayan and Finley A. Charney.
- “Design of Steel Buildings for Earthquake and Stability by Application of ASCE 7 and AISC 360,” by Shankar Nair, James O. Malley and John D. Hooper.
- “Current Steel Structures Research No. 27,” by Reidar Bjorhovde.
And a special focus on Non-Building Structures:
- “Seismic Design and Response of Crane-Supporting and Heavy
Industrial Steel Structures,” by Julien Richard, Sanda Koboevic and
- “Design of Braced Frames in Open Buildings for Wind Loading,” by W. Lee Shoemaker, Gregory A. Kopp, and Jon Galsworthy
Each quarterly current issue of EJ is available in digital format and free to the public until the next issue is published.
The complete collection of Engineering Journal articles is searchable at www.aisc.org/ej. Downloads of current and past articles in PDF format are free to AISC members and ePubs subscribers; just make sure you are logged into the AISC website (www.aisc.org) before searching. Non-members will be directed to the AISC Bookstore at www.aisc.org/store to purchase article downloads.
Have You Heard the ‘Father of LRFD’?
Posted by Tasha Weiss on September 28, 2011 at 10:05 AM.
Tune in to the 10th installment of AISC’s Steel Profiles podcast series to listen to a 37-minute interview with the ‘father of LRFD’ (Load and Resistance Factor Design), Ted Galambos, Ph. D., P.E, emeritus professor of structural engineering at the University of Minnesota in Minneapolis. Among his many industry contributions, Galambos is probably best known for his work on the development of the 1986 AISC/LRFD Specification, which earned him AISC’s prestigious T.R. Higgins award in 1981. His illustrious academic research and teaching career began at Lehigh University in 1959, then continued at Washington University in St. Louis and finally at the University of Minnesota.
In this latest AISC podcast, hear about how Galambos made it all the way from Budapest to North Dakota when he was just 19 years old, his dangerous yet fascinating research on the infamous Pruitt-Igoe housing project in St. Louis, and find out if he’ll be writing his LRFD memoirs anytime soon. Listen now at www.aisc.org/Podcasts.
Next month’s episode features an interview with international research expert, Reidar Bjorhovde, Ph.D., P.E.
If you’ve missed any of Steel Profiles’ first 10 conversations with steel experts, simply visit www.aisc.org/Podcasts where all episodes are available for easy listening and downloading. You can also access the podcast series on iTunes (search for “Steel Profiles”). Register for a free Steel Profiles subscription and each new monthly episode will automatically be downloaded for you.
UN-Reno Engineers Shake Trucks on a Curved Bridge
Posted by Tasha Weiss on September 27, 2011 at 10:09 AM.
Laboratory technician Chad Lyttle makes adjustments to sensor cables in final preparations for earthquake engineering tests at the University of Nevada, Reno’s Large-Scale Structures Lab. The first-ever tests on a bridge with truck traffic will help improve design regulations and standards and assure safer bridges during large earthquakes. Photo by Mike Wolterbeek, University of Nevada, Reno.
A team of engineers, including eight graduate students, at the University of Nevada, Reno are performing first-ever earthquake tests on a bridge with truck traffic to help frame changes to current codes and lead to safer bridges during strong earthquakes. Six full-size pickup trucks are placed on a 16-ft-high, 145-ft-long steel bridge as it moves vigorously atop four large 14-ft by 14-ft hydraulic shake tables in the university’s Large-Scale Structures Earthquake Engineering Laboratory.
“We took the bridge to its extreme, almost double what we planned at the outset,” Ian Buckle, professor of civil engineering and director of the large-scale structures lab, said. “Preliminarily we see that in low amplitude earthquakes the weight of the vehicles actually helps the seismic effects on the structure, while at higher amplitudes the trucks hinder considerably the bridges ability to withstand an earthquake.”
The 162-ton steel and concrete bridge, with 80 ft of curvature, fills the large high-bay lab from end-to-end. A three-minute video showing the largest motion applied to the bridge can be viewed by clicking on this link: http://bit.ly/qDW1Nq.
“Whether you saw the experiment in person or watch the video, remember that this is a 2/5 scale model, and the movement you see would be two and a half times greater on a full-scale bridge,” said Buckle, principal investigator of the research project. “It would be scary to be driving under those conditions.”
Buckle added that currently, bridges are not designed for the occurrence of heavy traffic and a large earthquake at the same time. “With increasing truck traffic and frequent congestion on city freeways, the likelihood of an earthquake occurring while a bridge is fully laden is now a possibility that should be considered in design. But there has been no agreement as to whether the presence of trucks helps or hurts the behavior of a bridge during an earthquake, and this experiment is intended to answer this question.”
The complete analysis will come after months of examining the many gigabytes of information gleaned from the 400 sensors placed on the bridge and trucks and the results of this work will be titled, “Seismic Effects on Multi-span Bridges with High Degrees of Horizontal Curvature”.
For more detailed information about the research project, visit the University of Nevada, Reno web site, here.
Ductile Design Text Works With New Seismic Provisions
Posted by Tom Klemens on September 26, 2011 at 1:35 PM.
The second edition of “Ductile Design of Steel Structures,” by Michel Bruneau, P.E., P. Eng., Chia-Ming Uang, Ph.D., and Rafael Sabelli, S.E., has been published by McGraw-Hill. Thoroughly revised throughout, this edition reflects the latest plastic and seismic design provisions and standards from the American Institute of Steel Construction (AISC) and the Canadian Standards Association (CSA). The new edition is compatible with the recently released 2010 AISC Seismic Provisions for Structural Steel Buildings (ANSI/AISC 341-10), which is available as a free download at www.aisc.org/2010SP.
The 928-page book covers steel material, cross-section, component, and system response for applications in plastic and seismic design, and provides practical guidance on how to incorporate these principles into structural design. Three new chapters address buckling-restrained braced frame design, steel plate shear wall design, and hysteretic energy dissipating systems and design strategies. Self-study problems are provided at the end of each chapter.
For more information, go to www.michelbruneau.com/DuctileDesign.htm.
Steel Shots: Happy SteelDay 2011!
Posted by Tasha Weiss on September 23, 2011 at 7:56 AM.
Federal Highway Administrator Victor Mendez (back middle) lends a hand to students from Howard University, participants in the 2011 AISC/ASCE Student Steel Bridge Competition. The students assembled and displayed their scaled steel bridge in a mock race against Virginia Tech as part of yesterday’s pre-SteelDay transportation and engineering event at the U.S. Department of Transportation in Washington, D.C. Click on the photo to see a group shot of Mendez (middle) with both teams and Andrew Herrmann, incoming president of the American Society of Civil Engineers (far right).
Today marks the structural steel industry’s third annual SteelDay and more than 200 events are taking place throughout the country to celebrate. Over the past two years, SteelDay has proven to be a huge success with thousands of people participating. This year is expected to draw in even more attendees as architects, engineers, contractors, students and others take the day to visit a structural steel facility, attend a learning presentation or a networking event.
SteelDay 2011 kicked off yesterday with a few pre-SteelDay events around the country, including a special event at the U.S. Department of Transportation in Washington, D.C. Dozens of attendees learned about innovative bridge technologies as well current issues surrounding the nation’s infrastructure and job creation. Speakers included Federal Highway Administrator Victor Mendez, Brian Raff of the National Steel Bridge Alliance, Lawrence Kavanagh, president of the Steel Market Development Institute, and Andrew Herrmann, incoming president of the American Society of Civil Engineers.
FHWA partnered with NSBA for this event to highlight both their “Every Day Counts” and “Highway For Life” initiatives. “Every Day Counts” is designed to identify and deploy innovation aimed at shortening project delivery, enhancing the safety of U.S. roadways and protecting the environment, while Highways for LIFE (HfL) aims to advance longer–lasting highway infrastructure using innovations to accomplish the fast construction of efficient and safe highways and bridges.
At the event, student teams from Howard University and Virginia Tech, participants in the 2011 ASCE/AISC Student Steel Bridge Competition, assembled and displayed their modular bridges in a mock race for guests to see, illustrating Accelerated Bridge Construction and the importance of engineering education and training. The annual Student Steel Bridge competition brings together the next generation of structural engineers to demonstrate their skills in steel design, steel fabrication, and teamwork in building scaled designed and fabricated bridges.
To find out more about what’s happening around the country for SteelDay, visit www.steelday.org. If you’re attending an event, share your SteelDay experience by submitting a video to AISC to be featured on the “SteelDay TV” channel on YouTube at www.youtube.com/SteelDaytv. You’ll also be entered into a drawing for a chance to win an iPad 2. For more information go to www.SteelDay.org/mySteelDay.
2011 AISC Certification Standard for Steel Bridge Fabricators Available
Posted by Tom Klemens on September 22, 2011 at 8:57 AM.
The new AISC standard for steel bridge fabricator certification is available for free downloading on the AISC web site at www.aisc.org/specifications (under Certification Standards at the bottom of the web page). Formally titled AISC Certification Program for Steel Bridge Fabricators Standard for Steel Bridges 2011 (AISC 205-11), the standard outlines three categories of fabricator certification based on three types of bridges: simple, intermediate, and advanced. The standard also includes requirements for a fracture-critical member certification endorsement.
The new standard is the culmination of several years of work by the AISC Certification Committee and its ad hoc bridge standard task group. It is modeled after the format of the AISC certification standard for structural steel building fabricators and the certification standard for bridge component manufacturers.
“This standard promotes a system-based approach to achieving quality in bridge fabrication,” said Charles J. Carter, S.E., P.E., Ph.D., AISC vice president and chief structural engineer. “Owners, general contractors and engineers who work with AISC-certified steel fabricators will benefit because this approach is more economical than the costs that often result from fixing what is found after trying to inspect quality into the product later.”
The standard is available as a free download at www.aisc.org/specifications (under Certification Standards at the bottom of the web page). The AISC Certification program expects to incorporate the new standard into its bridge fabricator certification program, replacing the current checklist-based certification program, over the next 24 months. Learn more about AISC Certification programs at www.aisc.org/certification.
EXPOSURE Wins Top SSDA Prize
Posted by Tom Klemens on September 21, 2011 at 10:12 AM.
A skeletal sculpture by Antony Gormley has been awarded the top prize in the 2011 Structural Steel Design Awards program. Begun in 1969, the program is administered by the British Constructional Steelwork Association and Tata Steel and recognizes steel-based structures built by U.K. or Republic of Ireland steelwork contractors around the world.
Gormley’s winning sculpture, dubbed Exposure, is 25 meters tall and was constructed in 2010 on a polder in Lelystad, the Netherlands. It depicts a giant crouching man, “a still point in a moving world,” as the sculptor wrote on his website, www.antonygormley.com, which includes a number of photos from different perspectives as well as a time-lapse video of its construction.
“The work cannot have a plinth,” Gormley wrote. “Over time, should the rising of the sea level mean that there has to be a rising of the dike, this means that there should be a progressive burying of the work.”
For an interesting two-minute YouTube video exploration of Exposure, accompanied by informative commentary in the notes box, go to http://bit.ly/nkrGIf.
To hear a short interview with the sculptor – his remarks are in English with Dutch subtitles – go to http://bit.ly/q6ojYP.
Prequalified Seismic Moment Connection Standard Available as a Free Download
Posted by Tasha Weiss on September 20, 2011 at 9:48 AM.
The 2010 AISC standard, Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic Applications (ANSI/AISC 358-10) is now available for free downloading on the AISC web site at www.aisc.org/aisc358. Released concurrently with a fully integrated supplement, the new standard now covers six connections:
- reduced beam section moment connections
- bolted stiffened and unstiffened extended end-plate moment connections
- bolted flange plate moment connections
- welded unreinforced flange-welded web moment connections
- Kaiser bolted bracket moment connections
- ConXtech CONXL moment connections
In addition to general requirements and limitations, each prequalified connection chapter includes a step-by-step design procedure.
The new standard has been approved by the AISC Connection Prequalification Review Panel (CPRP) and is ANSI-accredited. “The committee is pleased to be able to provide designers with more resources for seismic design,” said Ronald O. Hamburger, Chairman of the Committee. “Additional connections are already in the prequalification process, so our list of connections should continue to grow.” ANSI/AISC 358 is an essential companion to the AISC Seismic Provisions (ANSI/AISC 341-10), which outlines the requirements for the prequalification of seismic moment connections in Chapter K.
ANSI/AISC 358-10 and its integrated supplement, ANSI/AISC 358s1-11, are available as a single free download at www.aisc.org/aisc358. Learn more about this standard, as well as other current AISC specifications and codes available for free downloading, at www.aisc.org/specifications.
More Than 200 Events Planned Nationwide for SteelDay
Posted by Tasha Weiss on September 19, 2011 at 10:47 AM.
The structural steel industry’s third annual SteelDay is this Friday, September 23 — have you made your plans yet? If you haven’t registered for an event, there’s still time! Visit www.SteelDay.org/Events to find and register for a free event in your area. This year’s national event is expected to be celebrated at more than 200 locations around the country and, once again, offers plenty of opportunities to interact, learn and build.
Here is what you can expect to see at some of this year’s events:
- Steel Making and Recycling: Visit a steel mill and discover how steel is produced and recycled.
- HSS Producers: See the machinery and processes used to manufacture hollow structural sections (HSS) out of steel coil and learn about the differences between HSS and TS (tube shape) or HSS and pipe.
- Steel Service Centers: Learn how and why steel is always available by visiting a steel service center.
- Steel Fabrication: Witness the heart of the structural steel supply chain by visiting a steel fabricator and learn how off-site, controlled conditions and advanced computer numerical control (CNC) machinery ensure a consistently high-quality product and reduce or eliminate errors at the job site.
- Steel Installation: Learn about the steel assembly process - and in some event locations, even try out - the specialized equipment ironworkers use.
Special events will also be held in major metropolitan areas such as New York City, Chicago, Washington, D.C. and others.
For example, in downtown Chicago, AISC invites industry professionals to attend a special networking lunch and educational event at the Thompson Center Plaza. Guests will have the opportunity to meet new Chicago Building Commissioner Michael Merchant, explore a pictorial display tracking the history of steel framed construction and take a self-guided tour of famous steel buildings in Chicago. AISC Vice President John Cross will also present on the role of structural steel in the growth of Chicago and the nation. The evening prior to SteelDay, AISC welcomes local structural engineers into its headquarters to meet with staff and attend a special continuing education seminar by AISC Vice President Charlie Carter, P.E., S.E., Ph.D. Carter will present on the great structural engineering insights of the late Kurt Gustafson. Following a nearly four-decade career as a respected structural engineer, Gustafson spent seven years as AISC’s Director of Technical Assistance before passing away in 2010. You can register for this and all events at www.SteelDay.org/Events.
Click here to watch a SteelDay video preview on YouTube that gives a taste of what you can expect to see at this year’s events.
After attending an event, share your SteelDay experience by submitting a video to AISC to be featured on the “SteelDay TV” channel on YouTube at www.youtube.com/SteelDaytv. You’ll also be entered into a drawing for a chance to win an iPad 2. For information go to www.SteelDay.org/mySteelDay.
For everything SteelDay, visit www.SteelDay.org.