Structural Design of Deep Water Pontoon （深水浮箱的结构设计）.pdf

Ports 2013 © ASCE 2013 1087 Structural Design of Deep Water Pontoon Mooring Anchors Tripp Howard, P.E.1 2 3 , Bob Riley, S.E. , Ben Upsall, P.E. , Garry Horvitz, P.E., 4 L.E.G. 1KPFF Consulting Engineers, 101 Stewart Street, Suite 400, Seattle, WA 98101; PH (206) 382-0600; email: thoward@ 2KPFF Consulting Engineers, 101 Stewart Street, Suite 400, Seattle, WA 98101; PH (206) 382-0600; email: briley@ 3Hart Crowser Inc., 1700 Westlake Avenue N, Suite 200, Seattle, WA 98109; PH (206) 324-9530; email: ben.upsall@ 4Hart Crowser Inc., 1700 Westlake Avenue N, Suite 200, Seattle, WA 98109; PH (206) 324-9530; email: garry.horvitz@ ABSTRACT After nearly half a century of service, the world’s longest floating bridge is now clogged by traffic, showing its age, and in need of replacement. The Washington State Department of Transportation (WSDOT) is building a new State Route (SR) 520 floating bridge capable of withstanding heavier windstorms, and moving significantly more people and goods. Much like a large floating marine dock, the new bridge will consist of concrete pontoons moored to 58 deep water anchors by 8 miles of steel cables. The bathymetry and subsurface conditions of Lake Washington pose unique challenges for th