H&H provided preliminary and final design for the major rehabilitation of Unit 14 of the viaduct, which includes a double-leaf trunnion-style bascule bridge over the Menomonee River in Milwaukee, WI. The bascule span no longer operates, and the project will permanently fix the bridge in the closed position to allow for deck replacement and steel repairs of Unit 14. The project is currently under construction and focuses on transforming the movable double-leaf bascule span into a permanently fixed span, as it is no longer necessary for the bridge to open and close over the river.
The rehabilitation work includes replacing the open-grid steel deck on the bascule span with a new cast-in-place concrete deck and replacing the fiberglass sidewalk plates and supports with new concrete sidewalks. The concrete fixed spans on each side of the bascule span are being re-decked, while the bascule span superstructure steel is either replaced or removed to support the new concrete deck. The existing main bascule span steel girders, along with substructure steel on the vertical bents and superstructure steel on the fixed spans adjacent to the movable span, are being rehabilitated or replaced as needed.
Additionally, the project involves removing all movable bridge operating equipment, access platforms, and unnecessary electrical service and equipment. Repairs to the piers include removing timber dolphins and fencing and replacing them with new rubber fenders on the concrete pier faces. Structural steel throughout Unit 14 will be abrasive blast-cleaned and painted, and deteriorated steel rivets and bolts will be replaced.
As part of the project’s preservation efforts, the non-functional bridge operator’s house will be removed from the bridge and re-erected as a monument near the viaduct, while a selection of the bridge’s machinery gears will be displayed along the Hank Aaron State Trail. Plaques will also be installed at each end of the bridge, commemorating its listing in the National Register of Historic Places by the United States Department of the Interior. The project includes other miscellaneous rehabilitation items to maintain the bridge’s function and preserve its historical significance.
City of Milwaukee – 16th Street Bridge over the Menomonee River
