Loop the Lake Boardwalk Bridges

GRAEF completed the full detailed design, bidding, and construction management of two separate boardwalk bridges. One bridge is located in the City of Neenah spanning the Neenah channel. This bridge is 768 feet long with twelve 64-ft spans. The second bridge is located in the City of Menasha spanning the Menasha channel and is 715 feet long with ten 63-ft spans and one 84-ft span. Both bridges were steel girder structures supported on steel pipe pile bents and concrete piers. Timber under-decking supported a 14-ft clear width composite deck boardwalk with aluminum and cable railings. Mid-span of both bridges includes and observation bumpout with covered canopy allowing pedestrians and bikers to enjoy view while not impeding the through traffic.

Approaches on the Neenah bridge had to tie into the Arrowhead Park trail on one side and ended in a vacant lot along River St. approaches for both bridges included new parking, landscaping, benches and picnic tables. At Menasha, close proximity of a railroad spur created challenges that were solved by including a pile supported boardwalk switchback that met the railroad pedestrian crossing requirements.

Also at Menasha, the first span form Fox St. needed to be angled and lengthen to span a sanitary interceptor and the treatment plan discharge lines into the channel. During design, soil borings revealed an extremely dense hard pan and gravel substrate that required pre-boring for all pier pipe piling.