MoDOT Route K and Route N Bridges, Stoddard County

Summary

Kaskaskia Engineering Group, LLC (KEG) provided Structural Engineering services for two bridges in Stoddard County, Missouri.  Existing Bridge N0381 (Route N) required a deck replacement and Existing Bridge P0389 (Route K) severely deteriorated, needing to be replaced on the same general alignment. To minimize the construction duration, both bridges were closed completely for construction.

Project

Route N over Ditch No. 30 consisted of the complete deck replacement on the steel wide flange structure. In addition to replacing the deck, updated concrete barrier curbs were installed and the deck/stringers were made composite through the use of shear connectors. The Route K over Wolf Creek structure was completely replaced with an 83.5-foot simple span spread box beam bridge. The new structure consists of four spread box beams (27in x 48 in) with integral end bents, founded on cast-in-place galvanized concrete pipe piles. Due to the close spacing of the box beams, the deck was full depth cast-in-place concrete. The structure is in Seismic Category B, requiring special considerations for the fixity of the pipe piles to the end bents.

KEG’s role was to provide Quality Control for both structures. This included providing independent design reviews of the structural elements and generating the quantities needed for construction. Where differences were noted in the design methodology, both designer and checker were required to come to an agreement on the final design, which would be implemented in the design. The structural design and check were based on current MoDOT standards and AASHTO LRFD Bridge Design Specifications.

In addition to the design Quality Control, KEG was tasked with providing Quality Control measures for the plan development. This included ensuring the plans represented the design data in the calculations, while also following current MoDOT practices for detailing and specific state preferences.