IL Dept of Transportation Coal Creek Bridge, Phase II
Still utilizing its original structure, which was built in 1937, Coal Creek Bridge on U.S. Highway 6 in Rock Island County, Illinois, had deteriorated to the point that it needed to be replaced. To support future growth, a four-lane bridge was desired to replace the existing two-lane bridge; the Illinois Department of Transportation also wanted a plan in place to know that the bridge could accommodate Coal Creek floodwaters in the future if needed.
Shive-Hattery provided engineering services for the Coal Creek Bridge replacement. A 162-foot-long, four-lane, three-span steel beam bridge that stretches 74 feet in width was designed. Supported by solid-shaft concrete piers with spread footings and pile-supported integral abutments, the structure was created to not only be larger than the existing bridge, but also higher to accommodate potential floodwater. The project involved more than 1,000 feet of approach-roadway improvements to raise the grade of the bridge about two-and-a-half feet.
Taking the future into account, knowing that U.S. Highway 6 traffic counts will increase, the approach roadway from the west was designed to be four lanes, as was the bridge itself. Although the approach roadway on the east side of the bridge narrows back down to two lanes, Coal Creek Bridge can now accommodate a widened highway in the future if needed.
Shive-Hattery provided all Phase I and Phase II work, including field surveying; a hydraulic report; a structure report; type, size, and location (TS&L) plans; a project report; right-of-way documents; final plans; and specifications.
Because nearby wetlands were impacted by the widening of the bridge, constructed wetlands were built to compensate for what was removed as part of the Coal Creek Bridge rehabilitation project.
Moving from a two-lane rural bridge to a four-lane urban bridge prepares U.S. Highway 6 and Coal Creek Bridge in Rock Island County for higher traffic counts in the future. If U.S. Highway 6 is ever widened, the bridge is already designed to accommodate this change.
The bridge is new and structurally sound, and set to serve the area’s increasing transportation needs for decades to come.