LANSDOWNE BRIDGE REPLACEMENT

Euthenics provided engineering and surveying services for replacement of the Lansdowne Boulevard bridge (C.H. 171) over the East Branch of Crab Creek in Mahoning County, Ohio. Services included a structure type study, survey and basemapping, roadway and bridge design, utility coordination, hydraulic and scour analysis, floodplain coordination, and final construction plans. The existing bridge was a three-span continuous concrete slab on reinforced-concrete substructures with two in-water piers. The selected replacement uses concrete box beams with the proposed abutments in front of the existing abutments, allowing the piers to be removed and avoiding the major sanitary-sewer conflict associated with placing new abutments behind the existing structure. The new bridge is an approximately 45-foot single-span prestressed/precast concrete box-beam superstructure with a composite concrete deck supported on semi-integral abutments founded on piles. The roadway was reconstructed for approximately 230 feet to transition the bridge approaches to normal crown sections and improve drainage, with the replacement section carrying 10-foot lanes and paved shoulders. The project is within FEMA Zone A, so Euthenics evaluated existing and proposed hydraulic conditions and coordinated with the Local Floodplain Coordinator; the selected alternative improved headwater conditions, reduced flow velocities, removed the in-water piers, and met the county and FEMA no-rise requirement. Utility coordination addressed the existing 6-inch gas line, water main, overhead electric and telecommunications, and the 20-inch sanitary sewer. Euthenics prepared maintenance-of-traffic and detour plans for the roadway closure.