21 minute read
Spotlight
Crystal Bridges Museum of American Art
By Craig Schwitter, P.E. and Cristobal Correa, P.E.
Buro Happold Consulting Engineers, PC was an Outstanding Award Winner for the Crystal Bridges Museum of American Art project in the 2012 NCSEA Annual Excellence in Structural Engineering awards program (Category – New Buildings over $100 Million)
Crystal Bridges Museum of Art is an iconic museum inspired by the local Arkansas landscape and the exotic suspension bridges of Bhutan. The 201,000-square foot museum is a complex of eight buildings located in Bentonville, Arkansas. Designed by Safdie Architects, each of the eight buildings, although individually unique, relate to each other through a unified palette of concrete, wood, copper and glass. There are five “land” structures that nestle into the hillsides and three “water” structures that create a circular promenade on the site. The land buildings are set in the sloped hillsides of the creek ravine. Where there is only soil under the buildings, drilled piers provide vertical support. Lateral loads are taken back through floor diaphragms and distributed to grade beam-supported minipiles farther up the slope that are inserted into rock sound limestone. The sizes of the grade beams are typically 30 feet deep with widths varying from 30 to 64 inches to accommodate the minipile geometries. The drilled pier diameters range from 2 to 3.5 feet, with rock embedment depths of 3 to 18 feet. The reinforcement included number 8 bar reinforcements with number 4 spiral ties. The lower levels of the land buildings are concrete frames that feature either beams or flat slabs that span 20 to 30 feet and are column supported. The upper-level columns and retaining walls are spanned by curved laminated timber beams (glulams), 10.5 x 31 inches in cross section. The building roofs are made of locally sourced glulam beams with alternating strips of copper cladding and glazed skylights. The bridge buildings notable because of their hanging arch forms, represented a real engineering challenge. Their bases form concrete weir structures that serve as the floors and, in the case of the two spanning buildings, also control the streamflow to create the signature museum ponds. The roofs of these buildings are a series of nonrepeating glulam arches, each of which has a unique inner and outer radius. Each arch is broken into three segments and tapers at the ends, varying in cross section from 10 x 32 inches to 10 x 24 inches. These arches rest on pairs of 4-inch diameter stainless steel cables strung between heavy concrete abutments that support the roofs. The roofs and floors are connected by external steel facade mullions that both support the facades and impart additional stability to the roofs under live loads. The glulams are connected to each other by a series of T-shaped steel purlins, 5 x15 inches in cross section, located atop the glulam beams. Since the number of purlins is constant throughout the cross section, as the bridge roofs become wider, the spacing between the purlins gradually changes. This provides the T-shaped purlins with both a vertical and a horizontal inclination with respect to the glulams. The engineers also used smaller, secondary timber purlins to divide the roof into opaque and skylighted areas. These secondary purlins have ¾-inch cross bracing that provides the roof plane with a structural diaphragm. The roofs are based on catenary shapes that are created by the deflection of the cables. The structures are designed so that the cables carry all of the dead load. Once the dead loads of the roofs were installed, the cables deflected and attained their final geometries. The facade mullions were then added, connecting the glulam beams directly to the ground. This created stiffer load paths that carried any additional live loads from the roofs. The mullions supplement the horizontal diaphragm of the roofs and provide lateral stability under wind and seismic loading. The bridges are suspended from abutments at either end; these abutments rest on mat foundations that utilize shear keys and are located directly on rock. Rock anchors were installed along the rear portions of the abutments and sleeved through the abutments. Once the concrete for the abutments was placed, the anchors were pretensioned in order to resist the cable pull loads. The foundations of the peninsula-like Great Hall building are slightly different in that there is only one abutment. The cable structure is tied to rock anchors inserted into the pond for added stability. The design of typical and repeatable details that could effectively be used with the complex geometry of the roof was one of the principal challenges of this project. One of these is the visible connection between the cables and the glulams at the typical ball joint castings. The detail functioned as a universal joint within the degree of movement defined by the geometry of the Great Hall, which presented the most challenging conditions of all of the bridge buildings. The repeatable detail could accommodate the number of variations that would occur as each glulam advanced along the cable. Crystal Bridges, with its complex geometries, would not have been possible were it not for a high level of collaboration between the design team, contactors, and the owner, and the use of BIM and digital fabrication technologies in order to ensure that the complex geometries specified could be designed and built.▪
Craig Schwitter, P.E., is a Partner and Principal at Buro Happold. Craig can be reached at craig.schwitter@burohappold.com. Cristobal Correa, P.E., is an Associate Principal at Buro Happold. Cristobal can be reached at cristobal.correa@burohappold.com.
ASSOC I A T I O N S NATIONAL COUNCI L
NCSEA News
April 9, 2013
Repair of Construction Defects – Every Project Has Th em
David Flax, Euclid Chemical Company Th ere are construction defects on almost every job, unless it is a very small job or unless the owner is extremely fortunate. Th e list of likely defects includes cracks, spalls, rock pockets, delaminations, chips, gouges, rained on slabs, uneven slabs, etc. On a typical job, repairs may have to be done to slabs, or vertically, or overhead. Th is presentation will discuss identifying the defects, repair material selection, repair methods, surface preparation, bonding, curing, etc. In some cases it will be important for the repairs to be aesthetic as well as functional and we will cover how to accomplish that.
April 25, 2013
Designing Connections to HSS – Introduction to Moment and Truss Connections
Brad Fletcher, S.E., Atlas Tube Known for its strength and aesthetic appeal, the usage and popularity of hollow structural sections (HSS) continues to grow. Whether HSS is used as a primary structural support or as an architectural element, it is the designer’s responsibility to select and specify the type of connections that will be used. Th is webinar will provide engineers with an introduction to two of the most commonly-used types of connections for hollow structural sections. Topics covered will include key considerations in the design of moment and truss connections, review of resources available to assist designers, cost factors, and more.
STRUCTURAL ENGINEERS NCSEA CONTINUING EDUCATION
Diamond Reviewed Th ese courses will award 1.5 hours of continuing education. Approved for CE credit in all 50 States through the NCSEA Diamond Review Program. Time: 10:00 AM Pacifi c, 11:00 AM Mountain, 12:00 PM Central, 1:00 PM Eastern. Register at www.ncsea.com.
In Memoriam
Dr. W. Gene Corley, NCSEA President, 1996–1997
Gene Corley, left, receiving the 1999 NCSEA Service Award from NCSEA Board President Emile Troup. NCSEA mourns the passing of Dr. W. Gene Corley. He was a jewel in our crown, instrumental in founding, promoting, and maintaining everything NCSEA stands for, and, especially, in making structural engineering a recognized discipline across the nation. He will be sorely missed.
Jeanne Vogelzang, NCSEA Executive Director on behalf of the Board, sta & membership of NCSEA Requirements Change for SECB Certifi cation NCSEA Signs New Agreement with SECB
Th e National Council of Structural Engineers Associations (NCSEA) has signed a new partnering agreement with the Structural Engineering Certifi cation Board (SECB). Th e Structural Engineering Institute (SEI) also signed a new agreement with SECB. Th e primary purpose of these partnering agreements is to have all structural engineering professional organizations working together and speaking with a unifi ed voice. Th e agreements represent a signifi cant new step in this direction. Specifi c goals include: • To promote the structural engineering profession. • To promote structural engineering licensure in all
U.S. jurisdictions. • To promote meaningful continuing education for structural engineers. To encourage more NCSEA and SEI members to obtain SECB certifi cation, SECB has enacted a two-year minimum open enrollment method for licensed professional engineers practicing structural engineering to attain certifi cation based on experience and education. Th e license and/or registration must have been awarded on or before July 1, 2005 and must remain valid continuously through the time of application. Th e open enrollment period began January 1. In addition, SECB has reduced application fees for NCSEA and SEI members from $350 to $200. Th e reduced application fee will be available for a minimum period of two years and is a one-time (not annual) fee. For more details, or to view updates to the application requirements, go to www.secertboard.org/application. “Th e partnering agreements between SECB, NCSEA, and SEI demonstrate that there is a unifi ed voice in the structural engineering profession,” said Greg Soules, P.E., S.E., SECB, Chair the SECB Board of Directors.
CALL FOR ENTRIES
Highlighting the best examples of structural engineering ingenuity throughout the world Eight categories: • New Buildings under $10M • New Buildings $10M to $30M • New Buildings $30M to $100M • New Buildings over $100M • International Structures • Renovation/Retrofi t Structures • Other Structures • New Bridges/Transportation Structures Eligible projects must be substantially complete between 1.1.10 and 12.31.12. Entries are due Friday, July 12, 2013, and awards will be presented at the NCSEA Annual Conference September 20 in Atlanta.
More information and entry form at www.ncsea.com
NCSEA First Winter Leadership Forum a Huge Success!
The inaugural NCSEA Winter Leadership Forum is history, and the two-day event met and exceeded all expectations. Over 50 leaders and principals from a diverse group of structural engineering firms in the United States engaged in thought-provoking sessions, meaningful interaction, and networking in Tucson. Sessions included subjects like Developing the Next Generation of Structural Engineers, Key Financial Indicators for Success, Managing Multiple Deadlines and Expectations, and Establishing a Structural Engineering Training Program in Your Firm. The Forum also included an interactive Roundtable event where attendees participated and discussed a range of topics. This was the first year for the Leadership Forum, and plans are already underway for the 2014 event.
Don’t miss the video recap of the Winter Leadership Forum at www.ncsea.com!
Engineers from the following firms were represented at the 2013 NCSEA Winter Leadership Forum:
AHJ Engineers, PC KL&A, Inc. Arup Martin/Martin, Inc. ARW Engineers Mercer Engineering, PC Barter & Associates, Inc. Nayyar and Nayyar Int’l Inc. BHB Engineers NCI Group CH2MHILL PEAK Engineering Cives Corporation Reaveley Engineers + Assoc. David E. Groblewski, Rubinos & Mesia Engrs.
P.E., Inc. Ruby+Associates, Inc. DCI Engineers SESOL, Inc. Degenkolb Engineers Skidmore, Owings & Merrill Dibble Engineers, Inc. Sound Structures, Inc. DiBlasi Associates, P.C. Stantec Dunn Associates, Inc. Steven Schaefer Assoc. Gilsanz Murray Steficek TETER Architects & Engrs. Gregory P. Luth & Assoc. TGRWA, LLC (GPLA) The Di Salvo Ericson Grp Haskell Thornton Tomasetti IBI Group / Giffels, LLC Wallace Engineering Jacobs Engineering Grp Walter P Moore Jose I. Guerra, Inc. Weidlinger Associates Kiewit Power Engineers Wiss Janney Elstner Assoc.
NCSEA expresses its appreciation to platinum sponsor
for their support of the Winter Leadership Forum. “The Winter Leadership Forum was a nice change from the past Winter Institutes and afforded not only great learning opportunities from terrific speakers, but also a chance to meet and learn from other firm leaders from across the country.”
William D. Bast, P.E., S.E. Principal, Thornton Tomasetti
NCSEA News
T R U C TURAL S
ASSOC I A T I O N S NATIONAL COUNCI L
The Newsletter of the Structural Engineering Institute of ASCE Structural Columns
Last Chance to Register for the Structures 2013 Congress
Don’t miss this opportunity to attend this year’s Structures Congress.
Offerings this year include: • Two Pre-Conference Seminars on Sustainability and
Accelerated Bridge Construction • Eleven Tracks of Technical Sessions • Outstanding Keynote Speakers • CASE 2013 Spring Risk Management Convocation • Student Program • Young Professionals Program • Thursday Night SEI Welcome Reception • Friday Night Reception at the Heinz History Center • Comprehensive Exhibit Hall • Many Opportunities to Network • Over Sixty Committee Meetings • And Much More For more information about theStructures 2013 Congress and to register, visit www.asce.org/SEI.
Errata
SEI posts up-to-date errata information for our publications at www.asce.org/SEI. Click on “Publications” on our menu, and select “Errata.” If you have any errata that you would like to submit, please email it to Paul Sgambati at psgambati@asce.org. Your New PDH Tracker and Personalized Hub for Continuing Education
Manage your professional development and license renewal through ASCE’s new learning management system – myLearning. Track all your PDHs/CEUs, including those from other providers; obtain certificates of completion; take program-related exams; print or save transcripts of your professional development – all in one place! Make myLearning your personalized hub for continuing education and explore the comprehensive program catalogand track your PDHs. Visit the myLearning website at www.asce.org/mylearning/ and get started today.
LOCAL ACTIVITIES
The SEI Illinois Chapter hosted its 20th Biennial Lecture Series at the Union League Club of Chicago on March 6, March 20, April 3, and April 17 in 2013. These prestigious seminars featured distinguished speakers from all over North America, and attracted many talented professionals from the Chicago land area. For more information about this and other chapter activities, please see the chapter webpage at www.isasce.org/web/technical/structural.html. To get involved with the events and activities of your local SEI Chapter or Structural Technical Group (STG) http://content.seinstitute.org/committees/local.html. Local groups offer a variety of opportunities for professional development, student and community outreach, mentoring, scholarships, networking, and technical tours.
Be part of the cutting-edge technical program of the Structures Congress 2014 in Boston, April 3-5, 2014. The Structural Engineering Institute is now accepting session and presentation proposals for the Structures Congress 2014.
Key Dates
All Abstract and Session Proposals due June 12, 2013 Notification of Acceptance September 18, 2013 All Final Papers due December 18, 2013 (extensions not possible)
Structures Congress 2014 Call For Proposals
Session proposals can take two forms, a traditional session with 4 papers presented, or a panel session with no papers and perhaps more audience interaction. In addition, you can submit individual abstracts that may be combined with others to form cohesive sessions. Topics will include but are not limited to: Bridges Buildings Seismic Wind and Flood Loads Sustainability Business and Professional Practice Blast and Impact Loading Nonbuilding and Special Structures Nonstructural Systems and Components
Visit the Structures Congress 2014 website for more information and submission instructions http://content.asce.org/conferences/structures2014/call.html.
Timber Bridge Survey Announced
Brian Kukay (member of the SEI Technical Activities Division Timber Bridge Committee), along with students Logan Dunlap and Daniel Zieske of Montana Tech, are conducting a nationwide Survey of Timber Bridge Construction and Maintenance. The survey was developed with input from Sheila Duwadi of FHWA, Jim Wacker of ASCE and the Forest Products Laboratory, and Phil Pierce, Chair of the Timber Bridge Committee. The survey will determine the extent of the use of wood for vehicular bridges and to assist in resolving issues of concern that bridge owners might be experiencing. Results will be provided to the American Association of State Highway and Transportation Officials and may lead to potential further investigation and/or research. If your state would like to participate in this survey, but has yet to do so, please contact Brian Kukay at Montana Tech of the University of Montana, bkukay@mtech.edu or 406-496-4517.
Two SEI Members Added to National Academy of Engineering
Congratulations to the following SEI members for their election to the National Academy of Engineering, one of the most esteemed career honors an engineer may receive: • Gregory Deierlein, P.E., F. ASCE, civil and environmental engineering professor, Stanford
University, Stanford, Calif. For development and implementation of advanced structural analysis and design techniques. • Sharon Wood, M. ASCE, professor and chair, University of Texas civil, architectural, and environmental engineering department, Austin. For design of reinforced concrete structures and associated seismic instrumentation for extreme loadings and environments. Visit the NAE website at www.nae.edu to learn more about the National Academy of Engineering.
Save The Date – ASCE Annual 2013 Conference
Don’t miss the opportunity to attend and expand your professional knowledge October 10-12, 2013 in Charlotte, North Carolina. Join ASCE and industry professionals from across the globe in the “Queen City” to discover hot topics and the latest trends in Innovations in Project Financing. Visit the Annual 2013 Conference site at www.asce.org/Conferences/ASCE-143rd-Annual-Civil-Engineering-Conference to learn more about this year’s conference. Hope to see you in Charlotte.
New ASCE Structural Webinars Available
SEI partners with ASCE Continuing Education to present quality live interactive webinars on useful topics in structural engineering. Several new webinars are available: Wind Design for Components and Cladding April 4, 2013 Bill Coulbourne Roof Failure due to Snow Loading – 2010-11 Southern New England Case Study April 15, 2013 Michael O’Rourke Changes to the Nonbuilding Structures Provisions in ASCE 7-10 April 17, 2013 J.G. (Greg) Soules The Five Most Common Errors Made During Bridge Inspections April 22, 2013 Jennifer C. Laning Connection Solutions for Wood Framed Structures April 29, 2013 Tom Williamson Wind Tunnel Testing for Wind Loads on Structures May 1, 2013 Forrest J. Masters Evaluating Damage & Repairing Metal-Plate-Connected Wood Trusses May 15, 2013 Jim Vogt Seismic Assessment and Design of Pipelines March 27, 2013 Donald Ballantyne
Webinars are live interactive learning experiences. All you need is a computer with high-speed internet access and a phone. These events feature an expert speaker on practice-oriented technical and management topics relevant to civil engineers. Pay a single site fee and provide training for an unlimited number of engineers at that site for one low fee, and no cost or lost time for travel and lodging. ASCE’s experienced instructors deliver the training to your location, with minimal disruption in workflow – ideal for brown-bag lunch training. ASCE Webinars are completed in a short amount of time – generally 60 to 90 minutes – and staff can earn one or more PDHs for each Webinar. Visit the ASCE Continuing Education website for more details and to register: www.asce.org/conted.
CASE in Point
CASE Tool 1-1: Create a Culture for Managing Risks and Preventing Claims
Inject into your firm a culture of risk management. This is the first and most comprehensive tool offered on risk management in the engineering industry. It includes a video, a story board and role playing guide to involve your staff in the risk management discussion. If you want to put your firm’s personnel on the path to good risk management habits, this is where you start.
CASE Tool 1-2: Developing a Culture of Quality
Culture is hard to define in an organization, but it is a key part of what gives a design firm character. CASE Tool No. 1-2, Developing a Culture of Quality was developed to identify ways to drive quality into a firm’s culture. It is recognized that every firm will develop its own approach to developing a culture of quality, but following these 10 key areas offers a substantial starting point. The tool includes an attached white paper and PowerPoint presentation that can be customized to facilitate the overall discussion. You can purchase all CASE products at www.booksforengineers.com.
CASE Risk Management Convocation in Pittsburgh
The CASE Risk Management Convocation will be held in conjunction with the Structures Congress at the Westin Convention Center in Pittsburgh, PA, May 2-4, 2013. For more information and updates go to www.seinstitute.org. The following CASE Convocation sessions are scheduled to take place on Friday, May 3: 8:30 AM–10:00 AM – The Business of BIM Speaker: David Odeh, Odeh Engineers, Inc. 10:30 AM – 12 Noon – Trends in Effective Use of Commercial Software for Building Structural Design Speakers: Pedro Sifre & James Parker, Simpson, Gumpertz & Heger, Inc. 1:30 PM – 3:00 PM – Reviewing Contractor’s Electronic Models in Lieu of Hard Copy Shop Drawings Speakers: David Ruby, Ruby + Associates, Inc. 3:30 PM – 5:00 PM – BIM Validation: Modeling for Downstream Success Speakers: David Aucoin
Timing of ACEC Convention Opportune for Industry Advocacy
With Congress and the Administration again locked in a budget showdown, the upcoming ACEC Annual Convention in Washington, D.C., April 21-24, will provide a unique opportunity for ACEC’s “citizen lobbyists” to urge lawmakers to advance federal infrastructure programs essential to the nation’s growth. ACEC’s lobbying effort will promote the passage of water, transportation and energy initiatives that should receive bipartisan Congressional support. The Convention also includes a wide range of expert panels, including federal agency officials discussing new business opportunities. A Teaming Fair for small and large firms will also be a highlight. For more information on the ACEC Convention, go to the following link: www.acec.org/conferences/annual-13/.
You can follow ACEC Coalitions on Twitter – @ACECCoalitions.
Donate To The CASE Scholarship Fund!
The ACEC Council of American Structural Engineers (CASE) is currently seeking contributions to help make the structural engineering scholarship program a success. The CASE scholarship, administered by the ACEC College of Fellows, is awarded to a student seeking a Bachelor’s degree, at minimum, in an ABET-accredited engineering program. We have all witnessed the stiff competition from other disciplines and professions eager to obtain the best and brightest young talent from a dwindling pool of engineering graduates. One way to enhance the ability of students in pursuing their dreams to become professional engineers is to offer incentives in educational support. In addition, the CASE scholarship offers an excellent opportunity for your firm to recommend eligible candidates for our scholarship. If your firm already has a scholarship program, remember that potential candidates can also apply for the CASE Scholarship or any other ACEC scholarship currently available. Your monetary support is vital in helping CASE and ACEC increase scholarships to those students who are the future of our industry. All donations toward the program may be eligible for tax deduction and you don’t have to be an ACEC member to donate! Please contact Heather Talbert at htalbert@acec.org to donate.
A/E Industry’s Premier Leadership-Building Institute Filling Fast for September Class
Since its inception in 1995, the American Council of Engineering Companies’ prestigious Senior Executives Institute (SEI) has attracted public and private sector engineers and architects from firms of all sizes, locations and practice specialties. Executives – and up-and-coming executives – continue to be attracted by the Institute’s intense, highly interactive, energetic, exploratory, and challenging learning opportunities. In the course of five separate five-day sessions over an 18-month timeframe, participants acquire new high-level skills and insights that facilitate adaptability and foster innovative systems thinking to meet the challenges of a changed A/E/C business environment. The next SEI Class 19 meets in Washington, D.C. in September 2013 for its first session. Registration for remaining slots is available. Executives with at least five years’ experience managing professional design programs, departments, or firms are invited to register for this unique leadership-building opportunity. As always, course size is limited, allowing faculty to give personal attention, feedback, and coaching to every participant about their skills in management, communications, and leadership. SEI graduates say that a major benefit of the SEI experience is the relationships they build with each other during the program. Participants learn that they are not alone in the challenges they face both personally and professionally, and every SEI class has graduated to an ongoing alumni group that meets to continue the lifelong learning process and provide support. For more information, visit www.acec.org/education/sei/ or contact Deirdre McKenna, dmckenna@acec.org, or 202-682-4328.
CASE Business Practice Corner
If you would like more information on the items below, please contact Ed Bajer, ebajer@acec.org. Standard of Care: What the Judge can tell the Jury
There are various “instructions” a judge can give a jury in determining the standard of care for an engineer. Below is just one used (CA) that recognizes that an unsuccessful effort does not necessarily mean a breach of the standard of care. [A professional ] is not necessarily negligent just because [his/ her] efforts are unsuccessful or [he/she] makes an error that was reasonable under the circumstances. [A professional ] is negligent only if [he/she] was not as skillful, knowledgeable, or careful as another reasonable [professional] would have been in similar circumstances.
Recovering Payment on a Federal Project
The Miller Act was created to protect sub-contractors against non-payment by the prime contractor. A design firm faced with the risk of non-payment may only rely upon the protection of the Miller Act for compensation in limited circumstances. For a design firm, it depends on the nature of the services provided. If on-site services are not provided, it is clear they cannot use the Miller Act to recover payment. However, recovery under the act is possible when a designer performs on-site supervision or inspection duties in addition to “typical” design services such as the preparation of plans, details and specifications.
Gaining Mastery of the EJCDC General Conditions
Construction administration calls for a thorough knowledge of the general conditions of a contract. The more complete your grasp of the details of that document, the more perfect will be your mastery of the many situations which it controls. No important decision affecting the owner’s rights should be reached without consulting the general conditions, since something in them is probably affected by it. The new 2013 version of EJCDC General Conditions will be available very shortly, if not already available from ACEC. Check the ACEC website, acec.org, for availability. Look for the 2013 edition.
