Now I really am mad at MNDOT

This article from the Star Tribune says it all. See the Star Tribune Metro Section for orginal web version.

I-494 bridge cracks jam plans for fall opening
Laurie Blake, Star Tribune
August 5, 2005 BRIDGE0805


Hairline cracks in the concrete walls of the new Wakota Bridge must be fixed, and that may delay its late fall opening, the state bridge engineer said Thursday.
The new Mississippi River crossing for Interstate Hwy. 494 is being built as two spans -- five lanes in each direction. A delayed opening of the first span for westbound lanes would push back the start of construction on the second span for the eastbound lanes.
The opening planned for November or December is now uncertain because the cost of the repairs and the timetable for finishing them have become a matter of negotiation between the Minnesota Department of Transportation and the bridge contractor, Lunda Construction Co. The contractor has begun reinforcing the bridge with steel cables while the talks, which started in July, continue.
Construction area
"We are going to negotiate until we get a fair settlement for the state," said state bridge engineer Dan Dorgan.
MnDOT believes it is still possible to make the repairs in time for the original opening, but "it gets more difficult by the day to achieve it," Dorgan said.
The small cracks do not pose a safety threat, but they must be fixed because they give salt and water a place to corrode the concrete and shorten the serviceability of the bridge, Dorgan said. The state expects the bridge to last 75 to 100 years.
The old Wakota Bridge still carries two lanes of traffic in each direction. When the first of the two new spans is finished, all traffic will be shifted there. The old bridge will be torn down and the new eastbound part will be built in its place.
The new construction is part of a larger, $250 million project that includes a new interchange between I-494 and Hwy. 61 in Newport. Underway since 2002, the bridge project will relieve a major traffic choke point in the southeastern part of the metro area when it is completed in late 2007.
A repair plan
The cracking was caused by a faulty engineering design that assumed all bridge walls would carry the same load, Dorgan said.
HNTB Corp., a national design and engineering firm with offices in the Twin Cities, has admitted the mistake, outlined the repair plan and is redesigning the eastbound bridge -- at no cost to the state, Dorgan said.
Once negotiations determine the cost of making the repairs, MnDOT will ask HNTB to pay that cost as well, Dorgan said.
The company was retained to work on the repairs and redesign because its familiarity with the plans allowed it to make the fastest fix, Dorgan said. The state hired independent consultants to review the work.
About 40 percent of the first bridge span was built before the cracks were discovered by the MnDOT inspection staff last September. After that, construction continued with extra steel reinforcement, Dorgan said.
The repair plan calls for the use of steel tension cables inside the concrete boxes that form the bridge walls. The cables are pulled tight to lift the floor slightly, Dorgan said.
The same technique used on other bridges has successfully relieved the stress that causes the cracks, Dorgan said. The cracks also will be sealed to keep water out.
Laurie Blake is at lblake@startribune.com