Terry Ward column: Building a bridge while protecting community assets

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If you've watched the project updates that Red Wing City Engineer Jay Owens and I have done on Community Access Channel 6, you know I like to start with safety.

As of today, there continue to be no lost time accidents on the Red Wing Bridge project. The entire project team is committed to safety of all workers and we hope this track record continues.

Jay and I are scheduled for our next Channel 6 project update at noon Wednesday, April 4, at Red Wing City Hall. There are traffic changes coming in early April on the project that I feel are important for you to understand.

The first week of April, we are scheduled to close the slip ramp and Third Street between Potter and Plum for reconstruction. As a part of this closure, we will be routing traffic across a temporary bridge over Highway 61 to the new button hook ramp and signalized intersection with Highway 61.

Also, the second week of April, we are scheduled to implement the nighttime detour of Highway 61 once again to remove the remainder of the existing slip ramp bridge over Highway 61. This could take up to three consecutive nights. It will be similar to the detour we used overnight in the fall. We've prepared some graphical materials regarding these traffic impacts that can be viewed under Future Traffic Impacts at http://www.dot.state.mn.us/d6/projects/redwing-bridge

Please feel free to contact Jay Owens or me if you have any questions or concerns regarding these impacts.

One important item to continue to note is that the existing Eisenhower Bridge over the Mississippi River is not planned to be closed during construction until after traffic is moved to the new bridge in 2019.

Vibration monitoring

Last month, I promised this update would feature the vibration monitoring plan and efforts we are taking to protect and preserve the historical features associated with the Red Wing Bridge project. The Red Wing community had continued to have a focus on the history and cultural resources during development of the project and we've listened to your feedback.

So, let's start with identifying all the historic elements within the area of impact of our project. They include:

• The Mississippi River 9 foot channel

• The former Chicago, Milwaukee, St. Paul and Pacific Railroad corridor

• Barn Bluff Existing Bridge No. 9103 over Highway 61

• Eighteen buildings of historical significance

To ensure that construction operations have no adverse effect on any of these historic elements, our team is implementing site-specific measures for historic protections. We've facilitated a pre-condition survey and monitoring program for the Canadian Pacific Railway corridor within the project, performed a condition survey of Barn Bluff and set specific vibration limits during construction, performed historic building pre-construction and post-construction condition surveys and implemented vibration monitoring plans, and developed historic mitigation materials for the removal of Bridge No. 9013.

The Barn Bluff work was particularly interesting as we hired a geotechnical consultant who assessed the condition of the bluff with both drone surveys and non-destructive field inspections to develop Barn Bluff specific vibration limits during construction, which were included in our contract. This effort also led us to eliminate certain forms of construction operations adjacent to the bluff that are known to cause high levels of vibration, like pile driving.

Also, the vibration monitoring plan for Barn Bluff had both threshold values (or construction shut-down values) and limiting values (or warning values) set at 80 percent of the threshold values. Key field staff get instantaneous email alerts if the Barn Bluff vibration monitors reach either the limiting or threshold values.

So far, we haven't received any alerts. We felt Barn Bluff is important to the Red Wing community and we heard that message from you.

We will continue to do our best to ensure that we respect and value the concerns of the community.

Key partnerships

We continue to work toward the goal of having the new bridge open to traffic by fall of 2019 before we take down the existing bridge in this $63.4 million construction project. This project is a strong partnership that includes the Wisconsin Department of Transportation, the city of Red Wing, the Federal Highway Administration and our contractor, Zenith Tech Inc.

As part of the team's efforts, you will see Jay Owens and me together at various community events or on a bridge tour. We've been presenting information about the project to civic groups and we'd be happy to visit with your group or provide your organization or business with the necessary information about the project so you can keep your employees informed.

We've found that if you know more about the project, you can help others understand it and minimize any possible disruptions it might cause. We do regular updates on the Community Access Channel 6, so you can catch us there as we provide updates and field questions. We have a lot of good information that can help explain the project. You can learn more about the project or sign up for email updates by going to MnDOT's project website www.dot.state.mn.us/d6/projects/redwing-bridge/ or you can follow us on Facebook at https://www.facebook.com/RedWingBridgeProject/.