New SR-520 Bridge
SDI supplied and installed the post-tensioning (PT) systems for this entire project, consisting of the superstructure and 23 pontoon structures. WSDOT utilized a series of floating pontoons to support this massive structure. The massive pontoons, each measuring 360’ long by 28’ high and 60’ wide, were built on shore and were then floated out to the bridge site. Each pontoon required 120 anchorages and utilized SDI’s plastic duct, which is designed and fabricated in-house at its corporate headquarters in San Jose, CA. The SR-520 bridge is the longest floating bridge in the world.