Capital Tent Tie-Down


Date: 1980 & 2002


In 1980 helical anchors were installed on the grounds of the U.S. Capitol’s West Lawn. These anchors hold down the large, tension-membrane structures (“Band Shells”) in which concerts and other events take place during the warm months, including “A Capitol Fourth,” the Fourth of July concert and fireworks display. The structures must be capable of resisting 90 to 110 MPH wind load in the event of a storm.

Project Summary:

  • Helical Pile Type: 1 1/2″ Square Shaft
  • # of Helical Piles: 60 +
  • Location: Washiington, DC
  • Installation Depth: 20′ – 25′
  • Challenge/Unique Aspect: In the spring of 2002, a new (larger) band shell was created requiring twenty-nine newly installed helical anchors. Each anchor was subsequently fitted with chain shackles and individual steel housings with covers (trap doors). Each year the helical anchors are exposed and load tested to insure they can resist the uplift from any storm activity.
  • Certified Installer: Levelift Foundation Systems
  • General Contractor: National Park Service