To improve safety for drivers along Highway 24, CDOT developed a plan to upgrade the five-mile route in Lake County. This included reconstruction of two lanes and shoulders, new guardrails and flattening of the slopes. CDOT also needed to replace a deficiently sized structural plate pipe with a bridge that would span the Arkansas River.
Twin 12’ x 10’ cast-in-place concrete box culverts were originally proposed for the bridge project. However, goals aimed at keeping road closure time to a minimum and concerns over environmental impact led CDOT to consider other options. Tezak Heavy Equipment approached CDOT to propose CON/SPAN® as an alternate solution that promised to be cost efficient and installed quickly.
The precast arch structure was installed over the existing pipe, allowing the river to flow freely until the arch units could be installed and backfilled. Utilizing a conventional cut-and-cover method, Tezak was able to install the bridge with ease and remove the pipe. Once the footings were cast, installation was complete in three days.
“One of the main reasons we did this bridge option was to speed up the construction, since this is a major route for Leadville,” said Clinton Moyer, PE, Project Engineer for CDOT. “Also, aesthetically, it is a knockout compared to a twin box.”
The clear span structure also minimized the environmental impact to the river, which is home to native born brown trout. With the bottomless system, the streambed could easily be returned to its natural state.