SR 520: De-tensioning of the World’s Longest Post Tensioning (PT) Tendons

Schwager Davis, Inc. began work in 2016 on the complex de-commissioning of the SR 520 Floating Bridge in Seattle, Washington. At an impressive 7,580 ft., the SR 520 is the longest floating bridge in the world. No one had ever attempted detensioning such long tendons.  The stored energy within the tendons was enormous. SDI’s engineering team formulated an innovative solution to de-tension the existing 3,600 ft long bonded external tendons, rigorously tested it, and executed the record setting PT detensioning perfectly.