Mohican State Park pedestrian suspension bridge

Background

The previous bridge over the Clearfork-Mohican River in Mohican State Park, which connected a number of trails, was destroyed in a flood in 1969 and never replaced. The new walkway and structure must provide a minimum clearance of 10 feet above the river’s normal flow level, with support structures also preferred above that 10-foot elevation.

Challenge

Providing preliminary design through final engineering and construction support, Woolpert and our subconsultants (including one EDGE business entity) also provided geotechnical design and environmental services such as ecological survey, ODNR Scenic Rivers coordination, and a construction stormwater pollution prevention plan (SWPPP). Shop drawing reviews consisted of reinforcing steel and prefabricated elements, such as pin connections and cables. Review of concrete testing results and mill reports were also conducted along with periodic site observation and inspection.

Solution

Woolpert designed a new bridge that consists of a 124-foot-long suspended span supported on hinged timber towers on spread footings or micro-piles to rock. The stay anchors are gravity reinforced concrete blocks. The main span uses a swinging timber deck on stringers with hinge points every four feet. The design is context-sensitive and blends with the surroundings. The existing trail (approximately 4,500 feet in length) was upgraded by widening and placing gravel.

For environment work, approximately 25 cubic yards of soil was excavated as part of the foundation installation and sieved to search for cultural resource artifacts. A wetland delineation early in the project identified avoidance areas. Woolpert coordinated closely with Scenic Rivers to meet all requirements for stormwater pollution prevention and runoff control, tree clearing and replacement planting, and general riverine preservation. Taking the surrounding environment into consideration, tree removal was minimized and impacts to wetlands avoided.

Outcome

Upon completion of this project, Woolpert replaced the original bridge with a similar but more resilient structure. In addition, the trail north of the river was reconnected to the Gorge Overlook and another new trail loop south of the river. The existing trail was widened, and new gravel was placed.

Benefits

• The bridge construction minimized environmental impacts.
• The new bridge meets Scenic Rivers Expectations and blends with surroundings.
• Woolpert provided complete “turn-key” design services and construction oversight.