CH 20 over Quiver Creek Replacement
Mason County, Ilinois
CH 20 over Quiver Creek
HEI was selected by the Mason County Highway Department to provide preliminary engineering services for the replacement of the bridge carrying CH 20 over Quiver Creek. This project was funded with Illinois Special Bridge Program funds and Highway Safety Improvement Program funds. County Highway 20 is a major collector between Havana and Pekin, connecting small towns and unincorporated areas to cities and services not available in the rural area. Along this route, there is a national wildlife refuge, a state forest, local and state fish and wildlife areas, prime farm ground, and natural wetlands where endangered species have taken up home. Design criteria included accommodating a Bald Eagle’s nesting site, keeping the existing bridge and road open during construction for as long as possible, a Sole Source Aquifer, and the availability of materials in the rural area.
The existing bridge consisted of a three span haunched T-beam superstructure with a reinforced concrete deck on pile bent piers and abutments. The structure was 168-ft long and the driving surface was 24-ft wide. The roadway alignment featured a broken back horizontal curve with super-elevation on each end of the bridge. The Phase I engineering included substantial coordination for wetland preservation and endangered species protection.
The new structure consists of a three span, curved, steel plate girder superstructure, with a reinforced concrete deck on concrete stub abutments and fully encased concrete pile bent piers. The structure is 195-ft long and 37-ft wide with a 30 degree skew in addition to the curvature. The project also included reconstruction of 3,325-ft of County Highway 20 on a shifted alignment to correct the horizontal curvature and remove the broken back curve.