MCGrawHill - Sept-14_Cassidy Breaux - 11

First and 38 (Months): Let the Building Begin S ome say it looks like a football helmet. Others argue it’s an alien’s helmet. But everyone agrees on one thing. It’s impressive. And the challenges for the builders were equally as large as the size of the stadium they were building. In fact, just to prepare the site for the building to come, the construction team had to consider the complex geology of the site in the Woodbine formation, which included dense sand, shale, and sandstone, not to mention a water table at 20 feet. Then there was the accelerated schedule that imposed restrictions on design system selection; there were space limitations due to drilled shafts, utilities, and structures; high construction loading from a 500-ton crawler crane and six tower cranes in close proximity to the retaining wall; and the wall geometry, which has ﬁve 90-degree outside/reemergent corners. From the ground breaking in April 2006 to the completion of the excavation in September 2006, Mario Sinacola and Sons Excavation and Craig Olden, Inc. worked together and made it happen. “We were lucky on the weather when we started excavation,” said Jack Hill. At the time, Hill was the Director of Stadium Construction with Blue Star Development, but he has hung up his hard hat and today he’s the Cowboys Stadium General Manager. “We didn’t get a lot of rain. It was very hot and dry, which was a perfect way to start the project,” Hill 38 said. “And we had a good management and construction team throughout the process. The excavation and retention were tough, but Sinacola and Olden did a great job. The workforce in this area is really good.” The stadium sits on 73 acres and about 50 feet below street level, which required Mario Sinacola and Sons to move about 1.5 million cubic yards of soil. Because of the water table they ran into at 20 feet, a dewatering system had to be installed. At the height of excavation, there were 70 trucks per hour for 10 hours a day hauling out dirt. Working in tandem with the Sinacola crew was Craig Olden, Inc., which constructed the retaining wall. According to Trevor Bray, Vice President at Craig Olden, Inc., the method of construction was top down, which meant they installed the soil nail wall in lifts until the site was excavated to full depth. The 200,000-squarefoot wall is made up of more than 8,200 double corrosion protected nails and anchors (more than 75 miles in total), a drain mat, temporary reinforced shotcrete face, epoxy-coated studded plates for connection, a secondary drain mat and waterprooﬁng membrane, and a permanent reinforced castin-place concrete facing. The site geology required specialized equipment and work methods, which included modiﬁed Caterpillar-based integrated drills, that Special Advertising Supplement to Texas Construction 11

MCGrawHill - Sept-14_Cassidy Breaux

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