Flatiron is replacing a 1960s-era bridge north of Denver over the South Platte River on State Highway 44 in Colorado. The new bridge is 80 feet wide and increases traffic capacity from two lanes to four. Work on the $7 million project also includes the replacement of a bridge over an irrigation canal with a box culvert, roadway work, drainage, signing, striping and guardrail.
Flatiron installed girders over the river in May, 15 of which occurred over two night shifts in the first phase. Girders were installed in a slightly unusual sequence which required stacking due to the cranes being “boom bound”—a conflict resulting in reach limitation of cranes with the newly set girders.
Since then, crews have been working on the new bridge superstructure, including overhand forms, deck edge forms and reinforcing steel installation. Traffic is expected to be switched onto the new structure in August. Once traffic is detoured onto the new structure, phase two will begin, and the existing bridge will be demolished to make room to build the remainder of the new structure. In phase two, crews will install 21 girders.