At 3.1 million square feet, SoFi Stadium is one of the larg- est, most expensive stadiums in professional football his- tory. The stadium sits on the former site of the legendary Hollywood Park racetrack, an iconic fixture in Inglewood, California’s history. From opening in 1938 to its last race in 2013, the track was a hot spot that endured shut down during World War II, a renovation in the 90s and shortly after, a devastating fire. In 2014, the Hollywood Park Racetrack was purchased by a new owner with big plans for what would become SoFi Stadium. LOD 400 Constructible Model Ensures Accuracy in Complex Design SoFi stadium is the centerpiece of a 298-acre mixed- use development that includes retail, commercial office space, a hotel and residential units, and parks, and sits on a site 3.5 times the size of Disneyland. The stadium was designed by HKS Architects, the firm behind the $1.3 bil - lion retractable roof at AT&T Stadium in Arlington and $1 billion U.S. Bank Stadium in Minneapolis. Bringing NFL’s Largest Stadium to Life with Ingenuity, Cross-Team Collaboration and BIM By Lee Snyder
of the structure, the ability to model to a high level of detail in Tekla Structures was critical in making sure everything would fit together,” said Tim Rachow, senior project manager at DBM Vircon. “We mod - eled to LOD 400, down to nuts and bolts, of which there were thou- sands. Everything came together extremely well and that’s a testament to the planning and detail and accuracy of the Tekla model.” Challenging Connections and Seismic Considerations The project’s roof design required a plated boxed compression ring with large bi-directional tensioned cables that crossed high above the field below and supported the stadium’s 2.2 million-pound circular video screen. DBM Vircon and Schuff Steel worked closely with the project’s struc - tural engineer of record, Walter P Moore to account for deflection and ensure the roof could structurally respond to seismic forces indepen- dently of the bowl structure. Walter P Moore worked entirely in 3D, using a shared Tekla model created by DBM Vircon. “The compres - sion ring at the inner edge of the roof had a series of very complicated connections,” said Mark Waggoner, principal and lead roof designer at Walter P Moore. “We modeled the connections and created our draw- ings from the Tekla model. At the same time, we provided the portion of the model with those complex connections to DBM Vircon to plug
SoFi Stadium’s architecture reflects Southern California’s industry, lifestyle, geography, and landscape. Its roof and underground cis- terns collect and store rainwater, providing all of the development’s irrigation needs. The stadium’s aerodynamic shape and permeable flanks were designed to pull the ocean breeze into the seating bowl, giving fans the feeling of being in an outside venue. Situated three miles from LAX, FAA height restrictions required the seating bowl to sit 100 feet below the existing grade. This challenge ended up as one of the project’s most prominent features – indoor/outdoor paths that guide fans through landscaped environments leading to ameni- ties throughout the stadium. SoFi Stadium also raises the bar with an Ethylene Tetrafluoroethylene (ETFE) roof comprised of 302 unique picture frames, each varying be- tween 30,000 to 70,000 pounds in weight, that broadcasts live football and visuals. The roof is supported by a 1,450-ton, 75,000-foot-long double cable net system. Construction design and detailing firm DBM Vircon used Tekla Struc - tures, Trimble’s BIM solution, to model and detail the roof’s complex steelwork and extensive on-site temporary steelwork that would sup- port preassembly of large elements. “With the weight and geometry
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March 2022 csengineermag.com
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