Hastings Bridge, Minnesota

Project Status: Active with scheduled completion May 2013.

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 as developing the settlement mitigation and instrumentation plan for the North Embankment. DBA will provide foundation engineering services during construction, including evaluation of all load tests. Additional geotechnical services, including exploration services and some design services, are being 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 will include 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 bridge foundations will consist of spread footings bearing on dolostone bedrock. The remaining bridge foundations will utilize 42in diameter pipe piles. Several Statnamic load tests, both axial and lateral, will be performed on the pipe pile foundations.

Settlement mitigation is required beneath the North Embankment due to several relatively thick and deep strata of compressible fine-grained soils. The embankment will also be heavily instrumented to evaluate performance of the embankment and mitigation technique.

Photos by DBA: