I-35W Bridge Collapse - Week 42

Week 42 by Ivy Chang | September 28, 2010

Court-appointed panel begins settlement work

The Minnesota Supreme Court appointed three metro-area attorneys to a panel that will consider special compensation for victims of the Interstate 35W bridge collapse. The chief justice appointed this panel to consider claims, make offers and enter into settlement agreements derived from a $38-million fund set up by the Legislature. The maximum allowed for each victim who files is $400,000, and those accepting compensation must release the state from future claims.

Crews continue to place pre-cast segments

Crews completed hoisting the first two pre-cast segments of the main span into place on the south side of the I-35W Bridge on Sunday, May 23. The ringer crane sitting on the anchored barge in the Mississippi River lifted two 198-ton concrete segments to join the south approach span. Placing the segment is a precise procedure involving hydraulic jacks and detailed surveying.

The next steps are to pour concrete between the segments and between the first segment and the approach span, concrete curing, and post-tensioning work to prepare for the next segment.

Segments are threaded together with cables anchored at the south end of the span. That span was cast as a continuous piece of concrete to counterbalance the segments over the river. In the casting yard, crews have fewer than eight segments left to pour. More than 30 segments have been hauled to Bohemian Flats, and others are stored on the ramp off Washington Avenue due to a lack of space at Bohemian Flats.

Box girders create the bridge deck

Pre-cast segments are expected to be completely installed during the second week in June. With the first two segments in place, the bridge now looks like box girders with a finished superstructure. High-strength concrete with multiple levels of redundancy is in every part of the bridge, according to project managers.

Crews began work to demolish the old road bed south of the casting yard, poured concrete on the approach spans and bridge decks, continued work on the Second Street Bridge on the north side, built cast-in place retaining walls for the on and off ramps at University Avenue, and graded the north end of I-35W.

Increased construction and the traffic generated affected closings of more streets around the bridge as trucks brought additional supplies for the bridge and segment hauling continued.

When the first segments were hoisted on May 24, over 300 people were on the Tenth Street Bridge to watch the event and attend the Sidewalk Superintendent Talk.

Fun facts

The majority of the drilled shaft foundations supporting the bridge is complete. Concrete in the shafts has been tested and determined to have achieved strengths averaging 8,380 pounds per square inch, strong enough to support 91 fully loaded Boeing 777 aircraft.