Bending Around (Sprint) Center. Written by George F. Wendt and David Landis, P.E. of Walter P. Moore

When it comes to bending pipes, Chicago Metal excels as can be seen in the Sprint Center in downtown Kansas City.

Downloadable Document

Bending Around (Sprint) Center
By David Landis of Walter P. Moore and George F. Wendt of Chicago Metal Rolled Products
In Modern Steel Construction magazine, July 2008

DESIGN

The $276 million Sprint Center arena opened last October to a sell-out crowd cheering for Elton John and received rave reviews. This unique state-of-the-art arena is Kansas City’s newest downtown landmark and the centerpiece for the city’s downtown revitalization. Sprint Center arena was designed by a consortium of the nation’s leading sports facilities architectural firms who took the name Downtown Arena Design Team (DADT). The unprecedented team was comprised of HOK SVE, Ellerbe Beckett, 360 Architecture, and Rafael Architects. Walter P Moore, a leading sports facility engineer, was structural engineer of record. Together, this design team brought a level of leadership, passion and experience like no other.

This 18,500 seat state-of-the-art multipurpose arena is expected to host over 100 events per year and was designed with flexibility as a primary goal. Sprint Center will accommodate NBA basketball, NHL hockey, AFL arena football, concerts, circuses, and many other performances and special events. With retractable and variable rise seating to optimize sight lines, the arena can be reconfigured quickly to accommodate different events. The roof structure also gives Sprint Center extraordinary flexibility to host a wide variety of shows and stage configurations. In addition to code live and snow loads, the long-span roof was designed to support up to 425,000 pounds of show rigging for concerts plus an 80,000-pound scoreboard, four 8,000-pound speaker clusters and nearly a half mile of catwalk loaded with sports lighting, spotlights, and electrical and sound equipment.

Sprint Center’s most notable aesthetic design feature is its distinctive cladding system. Curved both vertically and horizontally, the faceted cladding system was designed to allow dramatic views inward and outward and is somewhat reminiscent of a pillowed crystal bowl. The faceted glazing, as well as varied frit patterns applied to the glazing, transforms the building’s appearance as sun angles and light conditions change throughout the day. At night, the arena glows like a colorful ornament, exhibiting the activities inside and beckoning to the surrounding city.

Walter P Moore investigated numerous schemes for structural support of the cladding with the architects and construction manager. In response to the architect’s desire for an elegant and non-distracting support structure, a system of curved vertical and horizontal pipe was selected. Curved horizontal 16” diameter HSS span up to 50 feet and are supported by curved vertical 16” diameter HSS spanning up to 48 feet. The horizontal HSS are moment connected with end plates to reduce deflections. Using moment connections enabled the engineer to economically minimize member sizes while still meeting strength requirements and deflection limits. End plate connections with oversized holes allowed for reasonable erection tolerances while providing economical moment connections.

The curtain wall support frame was designed and detailed such that it did not provide support for any of the floors or roof. Since the curved frame supports only the cladding system, it was not required to be fireproofed. However, the curtain wall system did need to accommodate floor and roof live load deflections and building drifts due to wind and seismic loads. Design building drifts and support frame movements to be accommodated by the cladding system were outlined on the structural drawings.

FABRICATION

AISC member Schuff Steel Midwest had responsibility for the entire structural steel package and engaged fellow AISC member Hillsdale Fabricators an Alberici Enterprise in St. Louis for fabrication of the curtain wall support frame. AISC Roller/Bender member Chicago Metal Rolled Products earned the contract from Schuff Steel and Hillsdale Fabricators to curve 750 tons of the16 inch diameter pipe that gives the structure its unique shape. According to the site architect, Craig Milde of DADT, “The steel really helped give the glass enclosed arena its unique shape. Refining the geometry to attain the desired enclosure shape was most challenging – 9 radius points in each of the four arena quadrants.”

With full-service plants in both Chicago and Kansas City, Chicago Metal was able to minimize construction time and cost because each plant contributed to the project. For example, raw material more readily available in Chicago was curved in Chicago then sent to Hillsdale Fabricators in St. Louis who in turn shipped the parts to Kansas City to be erected. On the other hand, material purchased in Kansas City that was shipped to Schuff’s facility in Ottawa, Kansas, was curved in Kansas City. As the project progressed, Chicago Metal was in frequent contact with the fabricators to insure that everything was fitting up well.

According to George Wendt, President of Chicago Metal, “we are so proud to have contributed to this iconic structure that will be the pride of Kansas City for years to come. We opened our plant in Kansas City to curve steel for customers west of the Mississippi with quicker delivery, lower freight costs and increased capacity. We are happy that the new Kansas City facility achieved these goals with its work on the Sprint Arena.”

During fabrication, the design, fabrication and erection teams collaborated extensively. Numerous planning meetings were held to discuss fabrication and erection issues, including geometry coordination, acceptable tolerances, erection sequence, and support frame movements expected due to thermal changes and construction progress. Clips for the curtain wall mullion attachments were welded to the curved horizontal pipes in Hillsdale’s fabrication shop. Ensuring that the geometry of the fabricated curved steel and the curtain wall matched when erected was critical. Craig Milde, on-site DADT architect, visited both Chicago Metal and Hillsdale Fabricators to monitor progress. Wendt also visited Hillsdale Fabricators.

The curtain wall support frame was primed in the shop. The final coating was applied in the field after erection.

ERECTION

Walter P Moore developed an erection sequence during design to minimize support frame deflections during curtain wall erection – adjacent bays of curved horizontals and their moment connections had to be completed prior to erecting a bay of curtain wall. Erection of the 2,204 fritted trapezoidal glass panels of many different sizes lagged erection of the steel frame by several bays.

To simplify erection, Walter P Moore designed compact connections that allowed for reasonable fabrication and construction tolerances. The bases of the curved verticals are connected with pin assemblies. Connections to the upper concourse floor and roof are made with slip-critical bolts in oversized holes. The curved horizontals are moment connected with end plates with slip-critical bolts in oversized holes and shim plates. With few exceptions, erection of the curved steel frame proceeded smoothly.

Construction tolerances for the curved steel frame were reduced from those in the AISC Code of Standard Practice to facilitate connection of cladding system. Any point along the steel support frame had to be erected to within 1” of the design location in any direction.

Greg Peterson of Hillsdale Fabricators reported that Chicago Metal did a great job curving the steel: “the pipes fit their fixtures perfectly.” Craig Milde, the on-site architect reported, “the first four verticals were delivered yesterday afternoon. I watched the first one be set this morning. You must have done good work: it slid right into place.”

TEAMWORK

From the initial decision on the part of the architectural firms to form a consortium of some of the leading stadium and arena design firms though the design process to curving, fabricating, and erecting the curtain wall, teamwork and constant communication were the hallmark of this project. Numerous planning sessions during design, fabrication and erection helped construction of the doubly curved curtain wall system and support steel proceed smoothly. The resulting structure, Sprint Center arena, shines brightly as the achievement of that collaboration and is Kansas City’s new jewel.

Owner: City of Kansas City, Missouri

Developer: Anschutz Entertainment Group and Icon Venue Group

Construction Manager: M.A. Mortenson Company

Architect of Record: Downtown Arena Design Team: HOK Sport, Ellerbe Becket, 360 Architecture, Rafael Architects

Structural Engineer of Record: Walter P Moore

Steel Fabricator: Schuff Steel Company and Hillsdale Fabricators an Alberici Enterprise

Steel Detailer: Dowco Consultants

Steel Erector: National Steel Constructors

Curtain Wall Supplier: Architectural Wall Systems

Roller/Bender: Chicago Metal Rolled Products

About the authors:
David Landis, P.E., is Senior Principal and Design Director in the Kansas City office of Walter P Moore and has been involved in the structural design of over 30 sports facilities. Walter P Moore is a multidisciplinary consulting engineering firm based in Houston, TX. DLandis@WalterPMoore.com.

George Wendt is President of Chicago Metal Rolled Products, a national leader in curving structural steel, steel sheet and steel plate for the construction industry. Founded in 1908, Chicago Metal operates full-service plants in Chicago and Kansas City. GWendt@cmrp.com.


Our work TESTIMONIALS
  • "A big thank you to your team. Your parts are receiving the most positive feedback possible. Your company has new fans here."
    Bruce E., Kansas
  • "Without CMRP able to roll these channels to my specifications, there was no way this beautiful round antenna would have ever worked. 
    Damon S., Wisconsin
  • "My customer has installed several truck loads worth of 36" x 160# WF beams you rolled and cambered for us. The quality is spot on."
    Justin J., Alabama
  • "The rolled stringers were right on the button as far as pitch and radius."
    Bob O., Illinois
  • "I really appreciate your company coming through on this order & expediting the material when you said you would.You stick by their word."
    Jason R., Missouri
  • "The last order of rings were the best that we have received from you. The flanges were all flat. Keep them coming like that."
    Lenny P., Ohio
  • "Thanks for OVER AND ABOVE EXCELLENT SERVICE.  The quality and accuracy of CMRP's work is outstanding"
    Peggy, Texas
  • "The ring looks good! The OD is dead on. Thank you for your concerns regarding our questions and responding so quickly. I was impressed!"
    Fran Z., Pennsylvania
  • "Please pass on to the workers, . . . (your) rings . . . were some of the best our fitter has seen."
    Jeff K., Illinois
  • "I want to thank CMRP for exceeding what you promised. You are ahead of schedule and the strakes are fitting great."
    Jim A., New York
  • "Your advice was a significant contribution to the project.  You provide excellent service and knowledge"
    John Z., Illinois
  • "These pipes were rolled DEAD ON. The shop guys said they had never seen a pipe come in and hit every point like that in a long long time."
    Joe C., Missouri
  • "The rolling on these rectangular tubes was absolutely perfect! Barely any adjustment needed to be made."
    Tom G., Massachusetts
  • “We just placed an order for Rolled Angle Rings & you delivered them to us within 2-1/2 days ... we are three states away.”
    Jim S., Pennsylvania
  • “I would like a quote on a spiral project. I have heard many good things about your quality and timeliness from other fabricators.”
    Ryan L., Utah
  • “The rolled beams were delivered yesterday and look very good. Thank you for great service!”
    Thomas S., Maine
  • “I’ve worked with CMRP for over 16 years and can rely on them for any size job and in any time frame. CMRP delivers every time.”
    Mindy, H., Indiana
  • “It is unbelievable how good a job you guys did rolling these beams.”
    Richard G., Canada
  • “You all helped us out greatly when no one else seemed they could. Everything worked out wonderfully!”
    Cliff P., Florida
  • “The parts are very impressive and the service was stellar. I will certainly be recommending you to anyone needing such services.”
    Randy W., Georgia
  • “We got everything we needed in a very short turnaround, I appreciate it.  We are happy to have a reliable source to turn to.”
    Russell P., Illinois
  • “Quote was great! Timely, appropriate, and frankly less money than we expected.”
    James L., New York
  • “CMRP immediately took action and shipped out my order the same day! This all happened like clockwork, allowing us to meet the deadline.”
    Margo R., Ohio
  • “We only use CMRP for our rolling needs. We can always depend on getting a finished product that is to our expectations or better.”
    David P., New York
  • “I wish everyone could get quotes back that fast! That is why we use you, fast response to quotes and questions and great quality!”
    Will F., Indiana
  • “Your quotes are always so well organized and thorough, I trust your work.”
    Jessica, South Carolina
  • “On larger more complex rolling items, I typically only go to Chicago Metal Rolled Products for pricing due to quality.”
    Kevin H., Pennsylvania
  • “Thanks for providing the material. First two sets were laid out and fabricated. Radius was excellent!”
    Brad, Iowa
  • “We really appreciate your work on this. Amazing attention for a smaller sized job. Thank you for coming through.”
    Erik J., New York
  • “The project was AMAZING! Thank you so much for your help. I really do appreciate it. Always a pleasure doing business with you.”
    Kelly E., Iowa
  • “Your salesman provided a quick quote with an offer to explain things we should take into account. It's known you guys do the best work.”
    Mark R., Maryland
  • “Thank you for your help with the project and for getting everything complete and shipped out in a such a timely fashion. You guys saved the day.”
    Ben B., Florida
  • “You guys did an amazing job on these stringers. We would NOT be having such a success story without your team's effort & patience!”
    David B., Oklahoma
  • “You gave me excellent service and help which I appreciated very much. Material was on time and right on spec.”
    Brian S., Pennsylvania
  • “Your positive attitude is noted & CMRP reputation in the steel industry is impressive. All of our locations will contact you in the future.”
    Dave B., North Carolina
  • “My boilermakers in the field had positive things to say about the quality and accuracy of the angles that you rolled. Thank you.”
    Walter L., New York
  • “The project is complete and our customer is very pleased. I appreciate your diligence and quality on this one.”
    Dusty A., Texas
  • “CMRP has been instrumental in our ability to deliver high quality & great looking parts. Any job, big or small, CMRP has come through.”
    Eddie C., Kansas
  • “Your rolled steel worked great! We check lengths & chord dimensions ...everything was within an 1/8".”
    Don L., Michigan
  • “We received our order on time and the level of workmanship is excellent!"
    Roger R., Georgia
  • “Your company did a great job rolling these parts. Our fab and installation is going very well thanks to the quality of your work."
    Ronnie S., North Carolina
  • “Your company is the only one that was able to give me a quote that was right on with my specs, everyone else had to modify at least one dimension."
    Adam S., Minnesota
  • “Thank you for the follow through & turn around time, it greatly helps in the environment that exists today."
    Don F., Nevada
  • “This was our first experience with your company & I was very impressed with all aspects."
    Rick N., Minnesota
  • “I want all to know your hard work and efforts have not gone without appreciation."
    Lance B., Minnesota
  • “The accuracy and quality of your product put a smile on our foremans face - that is hard to come by."
    Jonathan S., New York
  • “Competitive price. Beat the schedule. No complaints from the project site."
    Lane K., Florida
  • “We appreciate you working with our tight schedule and overdelivering on this project."
    Alyson M., Texas
  • “The rolled segments were perfect and priced right. We will definitely use you again."
    Joe M., Nebraska
  • “Your group is awesome to work with and greatly appreciated!"
    Tammie N., Kansas
  • “You did EVERYTHING correctly. That's why you guys are the best in the business!"
    Walt W., Florida
  • “It was very impressive to get such rapid service and a great product."
    Jeff L., Pennsylvania
  • “Very impressed with your speed and overall service!"
    Brian W., Iowa
  • “Great service, product looks good, arrived a day early. Thank you!"
    David C., New York
  • “Your work, as always, near perfect, timely, and accurate. Exactly the same for the last 40 years."
    Pat M., Wisconsin
  • “Absolutely fantastic job by your guys! The fit of the two parts in AWESOME!"
    Kenny R., Florida
  • “The other guys were off by 3/4", CMRP spot on. We won't even question where to send our rolled plates in the future."
    Brant M., Illinois
  • “Your guys responsiveness is way better than any vendor that I have ever dealt with!"
    Jay W., Minnesota
  • “I always appreciate your continual positive attitude even in some difficult situations."
    Christopher L., Illinois
  • “We could not be happier with the parts and customer service you and your team provided. We have never been disappointed."
    Rodney H., Virginia
  • “What an amazing first time experience!! Couldn't be happier!."
    Jason S., Indiana
  • “We consider your company to be one which we can always count on to be on time and accurate."
    Andre T., Missouri
  • “It was very easy working with your company. I will recommend your company to others."
    Jim R., Illinois
  • “You handle all of our orders quickly and efficiently. Working with you is a joy!"
    Patti W., Texas