Located at the confluence of two rivers, Glenwood Springs, Colorado is a picturesque tourist destination made famous by its bubbling hot springs, caverns and other recreational amenities. At historic Grand Avenue, two prominent bridges reached across I-70, the Colorado River and a rail corridor to connect the two sides of the City.
As part of a major 30-month legacy project to replace these vehicular and pedestrian crossings with updated, wider alternatives, the City wanted to relocate the iconic pedestrian bridge to cross the nearby Roaring Forks River. Although the 30-year-old bridge was designed to be disassembled and moved, three of its four sections were found to be in poor condition when inspected at the new site.
So the City contracted the Gould Construction design build team to provide a (mostly) new pedestrian connection. And Gould selected Big R Bridge to design and fabricate the new bridge with the same look and feel as the original, while incorporating its fourth span. This was a very interesting challenge for the Big R Bridge design team.
Section of old bridge is incorporated into unique design
The new 394′ Signature Bridge recreates the old design and incorporates an original 64′ end span. The other three spans of 80′, 150′ and 100′ were created at our Greeley, Colorado facility with an approach that simplified design, fabrication and installation.
- The existing bridge was a three-span continuous structure with an under-deck arch truss center span and box truss configurations for the end spans.
- Due to crane access issues, trying to provide a three-span continuous structure would not work.
- Instead, we designed the center span to be a 150′ under-deck arch truss configuration with a 15′ triangular truss cantilever on each end.
- The triangular truss cantilevers support the box truss end spans, which act as simple spans.
- Care was taken so the triangular truss cantilevers and the ends of the box trusses would look like a three-span continuous structure when, in fact, it wasn’t.
Big R Bridge’s Engineering Department worked closely with Gould Construction, the erector and SGM Engineers (the City’s Consultant) to assure that the stage construction would work and that all architectural considerations were met for this Signature Bridge solution.
Replica bridge has a few key differences
Naturally, there are some improvements inherent in our modern engineering and manufacturing quality — more robust truss designs, welding techniques, mitered end connections, mill scale removal, decking and railings — but most people feel the new bridge is a very good replica of the original.
The new crossing was officially opened to pedestrian and cycle traffic with a ribbon-cutting ceremony on February 16, 2017. It connects the Midland Trail (formerly Colorado Midland Railroad) and the Rio Grande Trail (formerly Rio Grande Railroad). The largest center span is 14′ wide and offers an unobstructed view up and down the river.