I-35W Bridge Collapse - Week 43

Week 43 by Ivy Chang | September 28, 2010

Bridge between Winona and Wisconsin closed

Another bridge across the Mississippi River closed when an inspector discovered corrosion and holes in the bridge’s gusset plates. Minnesota Department of Transportation officials closed the Highway 43 Bridge at Winona as a precaution in the aftermath of the Interstate 35W Bridge collapse last year.

The Winona bridge is the main artery from Winona to Wisconsin where it becomes Highway 54; about 11,600 vehicles cross the span daily.

In addition to rust and corrosion, inspectors also found some buckling of a gusset plate in one location on the deck truss. MnDOT Deputy Commissioner Khani Sahebjam said a preliminary analysis will require two weeks, and a more complete analysis of the bridge will be completed in July. Then, transportation officials will know whether to repair or replace the bridge, which had been scheduled for replacement in 2017.

Three main span segments placed

Crews continue to erect the main span of the I-35W Bridge and placed the second and third pre-cast segments on the south side at Pier 2 on June 3. They also placed the first set of pre-cast segment on the north side at Pier 3 northbound. On June 4 workers were securing all segments with post-tensioning steel roads and post-tensioning steel cables.

Construction geared up on the north side of the bridge with crews pouring concrete to complete the first bridge deck. In addition, a new bridge deck is under construction on the Second Street Bridge, on the north side, with dozers grading the surrounding area where the bridge goes under the I-35W Bridge.

New entrance and exit ramps are under construction at University Avenue while another crew is building cast-in-place retaining walls for the ramps. Crews began driving fence posts on both sides of the highway from University Avenue to Fourth Street Southeast to prepare the walls.

South side construction ahead of schedule

On the south side, crews have completed 112 pre-cast segments, hauled them from the casting yard to Bohemian Flats, graded the area south of the approach span where utilities are now completely installed, formed a road on the side of the south approach, and continued to demolish the old road bed on I-35W.

Neighboring streets are closed temporarily to deliver materials, haul main span segments, and allow equipment to reach various sites. Workers are at the I-35W Bridge site 24 hours a day to complete the project before December 24.