Hamon Infrastructure replaced the highway bridge carrying Washington Avenue in Golden over SH 58. As a part of this project, Hamon constructed two (2) signature pedestrian bridges on the north and south sides of the Washington Avenue roadway bridge.
Background
The pedestrian bridge trusses were box arches with the deck hung from the bottom chord. The curvature of the top chords of the truss was different from the curvature of the bottom chords. The deck hangers consisted of double 4×4 angles.
Each pedestrian bridge had an entry plaza meeting ADA requirements at either end of the bridge. They also had masonry and veneer entrance portals at each end of the bridge designed to simulate a mine entrance in keeping with Golden’s rich mining history.
Project Benefits
PRE-FABRICATION OF THE BRIDGES – In order to reduce the impact on traffic, Hamon pre-fabricated both pedestrian bridges in their entirety. The bridges were assembled on temporary shoring in the highway median both north and south of the Washington Avenue Bridge. Each bridge was then placed into position in one night thus minimizing traffic impacts and enhancing the safety of the traveling public.
VALUE ENGINEERING COST PROPOSAL – The original design included a cantilevered retaining wall on caissons below the northwest abutment. Once caisson drilling had started a differing site condition consisting of weak, caving soils was encountered. In order to mitigate the cost of the differing site condition, Hamon offered an alternate design for a soil nail and shotcrete retaining wall with a one-sided concrete face as a VECP. CDOT accepted the VECP and Hamon was able to not only mitigate the cost of the differing site condition but also realize as savings of $103,700 on the project.
