Years of severe winter weather and a collision with a horse trailer ultimately proved too much for a concrete pedestrian bridge in Minneapolis. As a result, Western Specialty Contractors – Minneapolis Branch recently contracted with S and S Development to restore the damaged bridge, which connects the four-story Ridgedale Office Center to its parking structure.
The pedestrian bridge was already deteriorating when it was the hit by the horse trailer, prompting the structure’s immediate repair. Western worked directly with engineering firm Walker Consultants to design a replacement bridge railing system and estimate the repair work.
The scope of work included:
- Removing the bridge’s old steel railing system on all sides
- Replacing the outer concrete edge
- Opening the precast plank’s outer core
After Western removed the old concrete edge, Walker inspected the structural components and initiated the design.
Western then installed new supplemental reinforcing steel embeds into the precast plank structure and poured a new supporting edge on the outside of either side of the bridge. To create the edge, Western utilized a fast-setting, ready-mix concrete from a local plant and placed the concrete using a conveyor system to speed up the process and complete the project before winter set in.
During the construction process, Western workers ran into unexpected damage that prompted a slight change in plans.
“After we removed the old railing, we found that the outermost edge of the precast planks had a shear crack running longitudinally on both sides of the bridge,” said Western Minneapolis Assistant Branch Manager David Grandbois. “It was determined that this had to be completely removed, and new reinforcing steel had to be embedded into the existing planks to allow for a new concrete edge to be poured before Western could install the new railings.”
Western performed additional concrete repairs on the underside of the pedestrian bridge and the abutments on either end. After completing all the concrete repairs, Western installed new galvanized railings and applied a traffic coating to protect the newly restored concrete deck. The project was completed in two months and within budget.
