Hoback Junction
Hoback, WY

The Hoback Junction project included over 1000 lineal feet of retaining wall, a single-span steel wildlife underpass, and a four-span steel bridge carrying US 89 over the Snake River.

Steamboat Structures, working with the contractor and WyDOT, developed the wall design and details per the owner’s standards. The retaining wall design was part of a value engineering approach to provide a more economical option for material unit prices and project schedule than that initially designed. The seismically loaded cast-in-place retaining walls ranged in height from 16 ft up to 33 ft. Steamboat Structures designed falsework plans for casting of the bridge deck and the concrete pier caps for the Snake River bridge. Steamboat Structures developed the demolition engineering plans for the existing steel bridge over the Snake River. The existing bridge was analyzed for heavy equipment loading during removal and evaluated for stability during the staged demolition of the girders.

The new Snake River bridge consists of spliced, continuous steel girders with a superstructure depth of over 9 ft. Engineered erection plans were also prepared for the new steel bridge over the Snake River and the Wildlife Underpass. Girder Stability analysis, bracing and rigging designs were provided for both bridges.