Silver Glen Road over Otter Creek
Baxter & Woodman provided Phase I and Phase II engineering services for the $2.1M replacement of Silver Glen Road Bridge over Otter Creek (S.N. 045-3122). The bridge had a two-span precast deck beam superstructure, built in 1984. In 2016, the bridge was severely load restricted after significant structural cracking was discovered in several of the beams. The Kane County Division of Transportation installed temporary shoring to remove the load restriction, and began a Phase I engineering project utilizing federal STP-Bridge funding.
Phase I bridge engineering services consisted of an Abbreviated Bridge Condition Report, Structure Type Study, and Type Size & Location drawings. Avoiding right-of-way acquisition was critical to the project schedule, so the study favored shallower structure types that would minimize impact to the roadway profile. A three-span concrete slab bridge was selected. A single-span pedestrian truss structure was built parallel to the main bridge.
Additional Phase I services included wetland delineation and mitigation plan, Northern Long Eared Bat (NLEB) field assessment, Preliminary Environmental Site Assessment (PESA), identifying geometric deficiencies, preparing cost estimates, and a Project Development Report. Floodplain modeling and hydraulic analysis were evaluated along with existing drainage issues to confirm all IDNR permit requirements were met.
Baxter & Woodman also completed a traffic study to evaluate various construction staging alternatives during Phase I. A three-stage concept allowed for uninterrupted pedestrian access, and temporary bridge traffic signals were utilized to maintain two-way traffic through the work zone. Phase II services consisted of preparing final plans, specifications, permits, and cost estimates. Coordination with IDOT/FHWA and Kane County was ongoing throughout the project.
Baxter & Woodman received a performance rating of “Excellent” from the County for Phase I of this project!