Oak Openings Corridor Trail (Phases 1 & 2)

Phases 1 and 2 of the Oak Openings corridor consisted of the topographic survey and detailed design of 2.55 miles of multi-use trail connecting Angola Road, through Wiregrass Lake, to Secor Metropark in Toledo. DGL was responsible for the civil design, including establishing the alignment and profile of the 12-foot-wide trail. The profile grade was designed to minimize the need for excavation and embankment while maintaining the required slopes to meet ADA requirements. The trail build-up consisted of a 2-inch surface course of crushed aggregate screenings on 4-inches of stabilized crushed aggregate (ODOT Item 411). Hydraulic calculations and sizing for several culverts at stream/ditch crossing were also performed as part of the design and subsequent county approval.

DGL also worked closely with the Lucas County Engineer’s office on the multiple asphalt approaches and signage for pedestrians at several at grade county road intersections to ensure the safest possible crossings for the trail users. The proposed trail build-up within the county right-of-way was 1.25-inches of a light traffic asphalt on 1.75-inches of an asphalt intermediate course on a 10-inch aggregate base. Geotextile fabric and geogrid were both used to aid in subgrade stabilization. We have found this to be the optimal build-up in terms of constructability, structural integrity, and cost effectiveness.

Due to sensitive environmental requirements, the Oak Openings Corridor project includes over 1,000 feet of precast concrete boardwalk system installed on helical piers through multiple wetland areas. Helical piles are able to be installed without producing spoils and the slightly elevated boardwalk allows shallow floodwaters to flow through an uninterrupted drainage pattern. DGL worked very closely with a local concrete products manufacturer to help provide substantial cost savings to the project. We provided engineering support to the local manufacturer for the design of the precast boardwalk system, including the reinforced concrete beams, reinforced concrete planks, pre-cast concrete curbs, incorporation of railings and connections to the helical piers.