Q: How do you move a 3.5-million-lb. bridge?
A: One inch at a time.
For the new Larpenteur Ave. Bridge over I-35E north of St. Paul, MN, MnDOT used an innovative slide-in bridge construction method that let it build the new bridge next to the existing bridge. It then removed the old bridge and slid the new structure into place, a distance of 84 ft., using hydraulic jacks. This sped up the time the bridge would be closed (from 110 days to 47) and reduced costs for the people who use the road, reduced impacts on area businesses and improved safety for workers and motorists.