MCGrawHill - Sept-14_Cassidy Breaux - 19

assemblies made by Uni-Systems. Each pin bearing assembly consists of ASTM A148, grade 50, and was cast in a custom sand mold. The pin bearing assembly is attached to the top of a 25-foot by 11foot concrete thrust block that receives the end of each arch. “The real enormity,” according to Aniol, “lies hidden below ground, as the thrust block column is anchored to a slurry wall box abutment that transfers the thrust into the surrounding soil.” The concrete slurry wall box abutment, conceived by Aniol in collaboration with Clyde N. Baker, S.E, P.E., consists of a series of subterranean, 36inch-thick, concrete-ﬁlled trenches creating a rectangular box measuring up to 18 feet wide, 176 feet long, and 71 feet deep. Mark Penny, Project Executive for Manhattan Construction, says the arches are his favorite part of the new stadium. “The arches are massive. It is a true arch (in that it supports the load in a curve), unlike in most other buildings. This created all sorts of challenges with accommodating the loads to the ground, but made it possible to have such a large, column-free space inside the building.” All of this, just to be able to build a domed 660,800-square-foot roof, the world’s longest single-span roof structure. Jerry Jones wanted to bring some of Image courtesy of Uni-Systems the old stadium into the new stadium, including the soaring box truss spans and the hole in the roof. Additionally, he wanted the hole to be able to be closed, allowing the stadium to be a multipurpose facility able to host concerts, the 2010 NBA All-Star Game, special events, the 2014 NCAA men’s basketball Final Four, the Cotton Bowl, soccer games, and, of course, Super Bowl XLV in 2011. (The new Cowboys Stadium beat out the Colts’ stadium in Indianapolis and the Cardinals’ stadium in Arizona.) The opening in the roof, which is 256 feet wide by 410 feet long, and visible from ﬁve miles in the air, is created by two bi-parting, retractable panels, each measuring 63,000 square feet and weighing almost 1.7 million pounds. The panels travel on two parallel rails along the top of the arches by a specially made drive system and meet at the 50-yard line. Although there are two other retractable roofs in North America, Cowboys Stadium has the steepest (at 23.9 degrees) and largest (660,800 square feet). That steepness is what forced Uni-Systems to come up with the new drive system. According to Justin Waldron, Structural Engineering Manager for Uni-Systems, past systems were either not economical or Special Advertising Supplement to Texas Construction 19

MCGrawHill - Sept-14_Cassidy Breaux

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