Category: Monthly Webinar South Dakota ABC and Monolithic Precast Box Culverts

July 22, 2021 1:00 pm

Steve Johnson, P.E., Chief Bridge Engineer, South Dakota Department of Transportation; Gerad A. Johnson, Vice President, A-G-E Corporation Contractors; and Q&A panel members Gary A. Johnson, President, A-G-E Corporation Contractors; and Steve Wagner, P.E., Owner, Baseline Consulting

Webinar Documents:
South Dakota ABC and Monolithic Precast Box Culverts - pdf of presentation
Q&A Session - pdf
News - July 22, 2021 - pdf of presentation

Description: In 2020 the South Dakota Department of Transportation let a project on SD 248 to replace two deficient three-span bridges with two box culverts. Concrete box culverts are the SDDOT’s preferred choice for small drainage structures to eliminate the safety hazard of guardrails and the future maintenance of bridge decks. The original plans allowed the typical options of field-cast or precast box culvert. The field-cast option was risky for washout due to the need to tie steel and set forms in the bottom of a drainageway and the time required to complete the work, in addition to the need for skilled labor that was hard to find and keep. The precast option required overly large pieces and mobilizing an overly large crane, among other constraints. The Contractor submitted a value engineering change proposal for a hybrid using the best of the precast with the best of the field-cast design, consistent with the SDDOT’s design requirement that the structure act as a monolithic unit. This presentation describes the SDDOT’s procedure to determine when ABC is appropriate for use, followed by design and construction details and lessons learned on the SD 248 bridge replacement.





Steve Johnson, P.E.
Chief Bridge Engineer
South Dakota Department of Transportation




Gerad A. Johnson
Vice President
A-G-E Corporation Contractors

Presentation Photos/Graphics:

1) Box culvert under cut and bed preparation

2) Setting precast single barrel sections

3) Setting barrel section inlet headwall

4) Setting wing wall footing wall


5) Setting precast inlet wing walls

6) Cast-in-place closure pour prep

7) A45 concrete pour between single precast barrel sections

8) Ready to pour floating apron slab

9) 95% finished product