The project involved final design plans, calculations, and specification for approximately 900 feet of roadway improvements and the removal and replacement of the existing 30-foot reinforced concrete slab structure carrying Fountain City Road over Haverstick Creek. The curved roadway alignment required the bridge superstructure to be placed on a new alignment while being super-elevated. The new integral abutments were placed on a 20° skew to the creek.
The roadway work included new horizontal and vertical alignments, drainage calculations, and right-of-way design. A hydraulic analysis was performed to ensure the new channel opening would adequately support the 50-year design storm. The bridge accommodates two lanes of traffic on a 36-foot roadway by providing a 41.5-foot, out-to-out bridge width.
The replacement single-span structure consists of a super-elevated reinforced concrete deck supported by six precast pre-stressed concrete I-girders. The deck was designed as a composite reinforced concrete slab integral with precast pre-stressed deck panels.
The precast pre-stressed concrete I-girders are supported by integral abutments. Due to the shallow rock depth, pile was pre-bored to a designed depth to provide adequate support and fixity for the structure.
Sharp curves in the road on either side of Bridge 34 caused concerns about safety prompting this rural Indiana county to realign the approaches and replace the bridge. One of the challenges involved the bridge’s location in karst terrain, which consists of porous limestone that has dissolved over time producing empty pockets, fissures, and sinkholes.
As a result Lochmueller Group suggested using micropiles and the new bridge became one of the first examples to do so in Indiana. Micropiles are constructed by drilling holes into rock for the bridge piles, then backfilling the holes with cement grout and reinforcing steel, making for smaller, higher-strength supports, perfect for avoiding the many patches of open rock common in karst areas.
Replacement of the bridge included realignment of CR 375 West to remove a tight curve in the alignment and to provide a safer intersection at US 150/SR 56. The new prestressed concrete I-beam bridge consists of 3 spans (66.25’; 80’; 66.25) on a curved alignment, with spans built along the short chords. The bridge is supported on abutment walls on spread footings with multi-row micropiles and hammerhead piers on spread footings with multi-row of micropiles.
This project was let by Illinois Department of Transportation (IDOT) as an extension of the reconstruction of the I-57/I-70 Interchange being designed by Lochmueller Group (Lochgroup). By compressing the design schedule from 18 to 12 months and proposing changes to the construction phasing, Lochgroup was able to save IDOT approximately $1.2 million.
The Little Wabash River Bridges are dual 5-span (83’-3”; 83’-3”; 126’-0”; 83’-3”; 83’-3”) prestressed structures. Lochgroup developed the final design plans for the replacement structures consisting of a Bulb-T superstructure supported on reinforced concrete piers and abutments on a 0° skew with expansion joints at each end. The total length of each structure is 465-foot, back-to-back of abutments and the clear roadway width on each structure is 44 feet. The bridges were built using staged construction and cofferdams. The bridges also incorporated IDOT’S new Bridge Smoothness Criteria for decks. The structure is in Seismic Performance Zone 2, requiring a detailed seismic analysis. The high potential for scour resulted in a complex structure design.
The project also involved approximately 1,725 feet of roadway work that incorporated a profile grade raise of 20 inches to accommodate the deep Bulb-T beams. Design efforts included design of the vertical alignment, drainage calculations, quantity calculations, and final plans and special provisions.