Hastings Bridge, Minnesota

Project Status: Active. All foundation work is complete. Main span arch installed September 2012. All four lanes open to traffic tentatively by the end of 2013, with construction completed spring, 2014.

Project Websites: Mn/DOT Hastings Bridge Project Home Page

DBA Client: Parsons Transportation Group, the project designer.

DBA Services: DBA is the project geotechnical engineer, responsible for the foundation design as well settlement mitigation and instrumentation plan for the North Embankment. DBA provided foundation engineering services during construction, including evaluation of all load tests. Additional geotechnical services, including exploration services and some design services, were provided to the project team from Braun Intertec via subcontract with DBA.

Project Highlights: The new bridge on TH 61 over the Mississippi River in Hastings, Minnesota includes a 545ft long free-standing arch main span and several relatively large approach spans. The finished bridge will have four lanes of traffic and a 12 foot wide common use pedestrian/bike path. The new bridge will allow additional parking and an artistic plaza area south of the river. An anti-icing system will be installed to help achieve the 100-year design life.
On the south side of the Mississippi River, the approach bridge foundations are spread footings bearing on dolostone bedrock. The south main span pier is supported on eight 4ft diameter rock socketed drilled shafts. The remaining bridge foundations utilize groups of 42in diameter pipe piles. Several Statnamic load tests, both axial and lateral, have been performed on the pipe pile foundations.

Settlement mitigation was required beneath the North Embankment due to several relatively thick and deep strata of compressible fine-grained soils. A driven pile column supported embankment was used to mitigate the settlement issues. The column supported embankment is heavily instrumented to evaluate performance of the embankment and mitigation technique.

Photos by DBA: