BNSF BIG LAKE BRIDGES

Fortescue, Missouri

Massman Construction Co. was awarded an emergency work contract to build 210 feet of new bridge for BNSF Railways across a flooded cornfield near Fortescue, Missouri. This was part of BNSF’s plan to help relieve water pressure along their tracks from the swollen Missouri River and allow for the reopening of this heavily traveled rail line. Mobilization began the following day, and within seven days construction had begun on the bridge at Mile Post 100.7 in what the Massman team deemed “Lake Fortescue.” As 24-hour, seven-days-a-week work started on the bridge, Massman was asked to submit a proposal for a second bridge near Mile Post 102.19, two miles west of the first bridge. Massman was given the notice to proceed on the second bridge, which included rehabilitation of an existing 132-foot bridge and adding 158 feet of new bridge to each end of the existing bridge. At the time the second bridge was awarded, the buildup of pressure on the north side of the track embankment had caused a 400-foot-wide, 35-foot-deep breach in the railroad embankment. This resulted in BNSF adding the installation of a steel sheet pile wall to close the breach. Both of the new bridges consisted of 30-foot precast concrete girder spans supported by bents consisting of precast concrete caps with embedded steel plates welded to H-Pile driven to bedrock. The use of cofferdams was required to allow the welded connection between the precast caps and H-pile to be performed in the dry. The rehab of the existing bridge required removing the three spans of steel girders before setting and anchoring precast concrete riser blocks on top of the two existing bents. This was required to raise the rail roughly 3.5 feet to meet the elevation at the new bridges. Both of the new bridges were completed two days ahead of schedule.