Dome

October 09, 2021

You can imagine my surprise when I turned on the Monday Night Football game just as it went into a weather delay.  Apparently, I was not the only one, as the camera panned to Jon Gruden, coach of the Las Vegas Raiders, as the referee informed him of the delay.  He looked up, pointed toward the air, and you could see him mouth the words, “We are in a dome.”  While the new SoFi Stadium in Los Angeles has a dome roof, the panels on the side of the dome were open on the sides beneath the dome.  That was combined with several lightening strikes in the area to delay the game for 40 minutes.  The dome is sponsored by Social Finance, Inc. (SoFi), an American online personal finance company based in San Francisco, One purpose of the dome was to block problems from weather.  For that, it did not work.

When I checked online, I found that SoFi Stadium was built to be “an unprecedented and unparalleled sports and entertainment destination” built in Inglewood, CA, by the Los Angeles Rams.  The dome is the first indoor-outdoor stadium to be constructed and is slated to be the home of the Los Angeles Rams and the Los Angeles Chargers.  The state-of-the-art stadium re-imagines the fan experience and will host a variety of events year-round, including Super Bowl LVI in 2022, the College Football Championship Game in 2023, and the Opening and Closing Ceremonies of the Olympic Games in 2028.  The dome is located on the site of the former Hollywood Park racetrack and serves as the centerpiece of a 298-acre mixed-use development featuring retail, commercial office space, a hotel, residential units, and outdoor parking spaces.  The $5 Billion SoFi facility is only the latest mega dome being built for NFL teams. 

The stadium is built with an arching steel truss compression ring supporting a double grid cable net roof covered with translucent Ethylene Tetrafluoroethylene (ETFE), an extremely durable, totally transparent, fully color printable, film that is considerably lighter in weight than glass.   The ETFE is then surrounded with perforated aluminum panels. The roof is the largest of its kind ever built, and is comprised of 302 ETFE panels, including 46 mechanized vents that allow the heat generated by more than 70,000 spectators to dissipate.  The massive roof consists of more than 1400-tons of double orthogonal grid steel, and approximately 67,000 tons of ETFE membrane, secondary steel, gutters, cross clamps, cable struts, and retractable vents.  The 20,000-ton steel truss compression ring reaches the ground at three points and has additional support from thirty-seven earthquake-resistant columns as high as 100-feet from grade.  The 13-acre stadium roof is open on three sides and is a separate structure seismically, isolated from the stadium bowl.  That means one could fall without the other.

Thoughts:  When I worked in Utah my office signed off on another innovative design (at the time) to protect against earthquakes, base isolators.  Salt Lake City is a highly active seismic zone, and the historic city/county courthouse was being protected.  The entire four-story limestone structure was jacked off its foundation and had a series of base isolators which serve as the new foundation points for the structure.  A base isolator provides a way to prevent a structure from having to move and follow the ground as it shakes during an earthquake.  Like the SoFi dome, this was a first of a kind.  Another unique feature of the dome stadium is that it is situated in the flight path of nearby Los Angeles International Airport.  Installation of 28,000 V-Pix LED lights on the roof created a 13-acre high-resolution video display that can be viewed from above.  I can hardly wait to get the latest advertisements as I fly into LAX.  Follow the science.  Do the work.  Change is coming and it starts with you.