Événement

ASCE Seattle Section Ports and Harbors Committee Monthly Dinner

After 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 over 8 miles of steel cables. Varying water depths, soil types, uses, and environmental loads make anchoring this floating structure challenging. The water depths at the anchor locations vary from 30 feet to 210 feet, and subsurface conditions range from very dense to very soft and include soils with unique engineering properties. Ultimately three different types of anchors were used to meet these challenges: drilled shafts, gravity anchors, and fluke anchors.

This presentation will discuss some of the challenging aspects of the design and construction of the mooring anchors for this complex project.

Speaker: Tripp Howard, PE, Structural Engineer, KPFF Consulting Engineers
Tripp Howard is a professional structural engineer with more than 15 years of experience in the structural design, inspection, and repair of numerous waterfront, industrial, commercial, and transportation related structures. He holds a Bachelor's degree in Civil Engineering from the Georgia Institute of Technology and is a member of the American Society of Civil Engineers, the American Institute of Steel Construction, and the Pile Driving Contractors Association. Mr. Howard is currently a senior structural engineer with KPFF Special Projects Division, a consulting engineering firm in Seattle Washington that provides project management, planning, civil & structural engineering, machinery design, and construction management on a wide range of project types through all stages of development. His recent experience includes serving as a senior structural engineer for the design of the pontoon mooring anchors for the new State Route 520 Floating Bridge over Lake Washington.