U2 Concert Stage at Vanderbilt University’s Dudley Field – Nashville, TN

The stage known as the “Claw” was erected at Vanderbilt Stadium (Dudley Field) for the July 2, 2011 concert before 40,000 frenzied fans. Buried beneath the surface of the football field were two 100-year-old brick sewers, and these 54 inch and 87 inch diameter sewers that were still in use lay a mere three feet below the ground surface. The structural loads imposed by the stage and its construction might have damaged the sewers or worse, cause them to collapse. The seriousness of this situation was recognized after the concert date was established and the need for engineering evaluation was placed at high priority. TTL was hired by Vanderbilt University to evaluate the impact of the structural loads and construction loads on the century-old sewer lines and determine if they could safely support the “Claw”. TTL utilized modern finite element analysis combined with historical publications and new video reconnaissance footage to determine if the brick storm sewers could indeed withstand the loads from the stage. This data was utilized by the project team to select means and methods of successfully transferring the heavy loads of the stage structure and the lifting apparatus to the turf subgrade above the sewers without damaging them. Construction of the stage went on as scheduled without incident….and the show went on.