I-35W Bridge Collapse - Week 46

Week 46 by Ivy Chang | September 28, 2010

Legislators take a bridge tour

The Minnesota Department of Transportation hosted key legislators on a tour of the I-35W Bridge on Tuesday, June 24. Most lawmakers were surprised at the construction speed and some praised the work of construction crews. But the praise was overshadowed by politics of the bridge collapse and the pressure to complete the bridge for the Republican National Convention, which takes place in St. Paul beginning on September 1.

During the same morning, Gov. Tim Pawlenty said a legislative report linking a lack of funding at MnDOT to a lack of maintenance of the collapsed bridge was off base. He reminded the public that the National Transportation Safety Board continues to conduct its investigation and has not issued its conclusions. The NTSB has indicated that under-designed gusset plates may be a major cause of the collapse.

Joint legislative panel seeks MnDOT answers

In the afternoon, the chair of the Senate Transportation Committee conducted a joint legislative panel investigating the bridge collapse. Legislators pointed to the Gray Plant Mooty report and asked MnDOT officials to respond. MnDOT officials said many suggested changes in the report are being adopted, and that Gray Plant Mooty misunderstood the complexities of bridge maintenance and engineering.

Among the changes is a more clearly defined distribution of responsibilities between the central administration and the eight district offices.

New MnDOT deputy commissioner Khani Sahebjam finally asked the legislators to "please, trust us on this," because he said the trust from legislators and the public has diminished.

But a state senator said MnDOT is not taking the findings seriously enough and has not acknowledged the serious nature of this report.

Bridge segments are half complete

As of June 25, half of the pre-cast concrete segments have been installed over the Mississippi River, and the barge crane will continue to install up to six segments a day until all 120 segments are placed.

A painting crew continues to paint Span 1 on the south side of the river with Snowbound white paint and is beginning to paint Span 3 on the north side. Cemstone is setting up a concrete batch plant to prepare for paving sections of the I-35W roadway north of Abutment 5. Concrete pouring will begin this week on the northbound lanes of Span 4, which connects Pier 4 and Abutment 5 on the north side.

Another crew is installing fences along the highway from University Avenue to Fourth Street Southeast. Foundations for street lights and signs at the entrance and exit ramps began at University Avenue and Washington Avenue, which run parallel to each other over I-35W. The Second Street Bridge is partially paved.

Road paving begins; construction is ahead of schedule

The concrete crushing machine was moved and set up at Abutment 1 on the south side. As crews complete demolition of the old I-35W roadbed, they will use the crusher to break large chunks of concrete into gravel that will be recycled as the base for the new roadway. Following paving, crews will make cuts in the concrete to prevent cracking.

Work continues 24 hours each day, seven days a week, producing much noise from the crusher, backup alarms on trucks, and concrete sawing. Traffic is re-routed during hauling of the main span segments to Bohemian Flats and other deliveries.

Flatiron-Manson Joint Venture and MnDOT said the work is ahead of schedule and hope to open the bridge to traffic in September. MnDOT’s project manager, Jon Chiglo, denied that they’ve attempted to finish the construction by the Republican National Convention.