• Overview
• Past Projects
• New Designs
• Articles
• Awards

Tell everyone at (Dynamic Structures) that it was a privilege to work with them. The equipment is high quality and the speed with which you were able to deliver it was incredible."

Stephen Rowe
Ride Technical Manager, Universal Creative (Japan)

Amgen Helix Pedestrian Bridge – Seattle, WA

 

 

This 400-foot pedestrian overpass was built for the world’s largest biotechnology company, Amgen, and was designed to evoke the shape of a helical DNA molecule.

The build-site had extremely challenging access limitations (over multiple rail lines), and needed to be engineered to allow assembly and erection of large components with minimal interruption of rail operations. The project also challenged conventional bridge design by including deformed geometry in both horizontal and vertical directions. The deformation (camber) needed to be specifically engineered to ensure that gravity would pull the bridge into its final correct architectural shape.

Extreme accuracy was required in the fabrication of the deck and arch components in order to meet tight tolerance requirements. The deck members, designed with heavy walled built-up plate sections, required carefully planned weld sequences and presets to avoid heat distortion often associated with this amount of extensive welding. The curved arch sections were built with high-strength (70ksi) steel pipe and were trial-fit section by section to ensure the final positioning would exactly match the target geometry.

The bridge met all aspects of the specification and fully realized the architect’s vision. Since completion, the Amgen Helix Bridge has received positive publicity, including a number of awards including:

• American Society of Civil Engineers 

Outstanding Project Award for Excellence in Structural Engineering

• The National Council of Structural Engineers Association

Outstanding Project Award

• Canadian Institute of Steel Construction

Krentz Award for Outstanding Steel Structure

More Images