Case study | Structural Engineering
MoDOT Bridges A8989 and A8990, New Madrid County
Details
Owner
Missouri Department of Transportation
Client
Garver, L.L.C.
Project Cost
$44,100 (KEG Fee)
Status
Completed December 2020 (Design)
Summary
Kaskaskia Engineering Group, LLC (KEG) provided structural design services for two bridges as part of a bundle of seven bridges in MoDOT’s Southeast District. The two bridges are Route H over Ash Slough Ditch and Route H over Drainage Ditch in New Madrid County, Missouri.
Project
The original structures were three-span structures with simply supported wide-flange beams with pile bent end bents and intermediate bents. The structures were deemed structurally deficient, per the structural inventory and appraisal information provided by MoDOT.
The replacement structures will each consist of a single-span bridge with no skew. The new structures measure 77’- 6” from back-to-back of abutments and 74’ from the centerline of bearing to the centerline of bearing, with a 24’ roadway and 16” Type H (32” single slope) barriers on each side. The bridges carry two, 11’ traffic lanes and 1’ shoulders. The structures will be constructed in one stage with the roadways closed to traffic during construction.
The superstructures consist of a cast-in-place concrete deck supported by precast prestressed 27” concrete box beams. The substructure units consist of integral abutments supported by galvanized cast-in-place concrete piles. The wing walls for these bridges are flared out perpendicular to the roadway.
As part of the design task, KEG coordinated closely between both the roadway design and the geotechnical engineers on the project.
