Mistake forces construction crews to redo $23M project

A contractor’s error during the construction of one of Iowa’s largest and most expensive bridge projects is requiring the $23 million project to be redone, KCCI Des Moines reports.

Construction crews were tasked with building a safer bridge on the intersection of Interstate 35 and Highway 30 in Des Moines, Iowa, due to numerous crashes that have taken place at the site over the years. However, some of the ramps built during the new construction process were designed with curves that were too sharp, according to Iowa Department of Transportation (Iowa DOT) representatives.

Crews are now being tasked with tearing down six brand-new bridge piers and their corresponding ramps because the heights were incorrectly calculated during the building process.

"When they were constructed, they weren't constructed at the right elevation," Scott Dockstader, an Iowa DOT engineer in charge of the project, said according to KCCI Des Moines. "Obviously, it's disappointing.”

Construction of the bridge began in 2016, but it wasn’t until several weeks ago that Iowa DOT officials and the contractor—Harmony, Minnesota-based Minnowa Construction—noticed the issue.

"A construction survey [was performed] where they didn't get it at the right elevation and the anchor sleeves just got moved around when they were pouring the concrete, more than likely," Dockstader said.

The piers will be utilized to hold steel beams that support the bridge deck, but the anchor sleeves that would connect to these beams are out of place and off by several inches. Crews will have to jackhammer out and repour new concrete to get these anchor sleeves to the correct height.

The errors are being chalked up to human error on the part of Minnowa Construction, as the plans were reportedly accurate.

Dockstader said that Minnowa had 240 days to complete the bridge, which was scheduled to be completed by the end of the year, but that it will now be delayed. Minnowa must pay $5,500 per day the bridge is delayed, with no additional expense going to Iowa taxpayers.

"It's a bid item. … If they have additional costs for the repair work that wasn't our responsibility, it's just additional costs they have that will come out of their project's costs," Dockstader said.

Keith Brunning, owner of Minnowa Construction, acknowledged the severity of the error, according to the report, and said that the company is working both to find the cause of the issue and ways to expedite the repairs.

It is estimated that jackhammering out the existing concrete of the piers will take two weeks per pier.