Contractors must consider the health of aging Zoo Interchange bridges under the three spans that will be repaired as part of an emergency contract.
The request for proposals for emergency repairs to the Milwaukee interchange gives contractors a lot of leeway in deciding how to remove and replace three bridges. Depending on their method, contractors might need to move or rebuild two other bridges, referred to as 101 and 104, that pass below the bridges that must be repaired.
“You have to put in there exactly how you are going to impact the ramps below, and that would be 104 and 101,” said Chris Klein, executive assistant to Wisconsin Department of Transportation Secretary Frank Busalacchi.
Bridges 101 and 104 carry traffic on northbound and southbound U.S. Highway 45, respectively.
The status of the U.S. 45 bridges was brought up by WisDOT planners during Tuesday’s pre-bid meeting for contractors interested in chasing the $12 million to $22 million contract. Company representatives at the meeting included those from bridge builders Zenith Tech Inc., Waukesha, and Edward Kraemer & Sons Inc., Plain, two contractors that were part of the Marquette Constructors LLC joint venture that built most of the Marquette Interchange.
WisDOT on Nov. 19 released an RFP for the project. Proposals must be submitted by Nov. 30.
Pat Goss, executive director of the Wisconsin Transportation Builders Association, said the way WisDOT is bidding out the job should be good for contractors because it gives them flexibility.
“I think when it’s somewhat open-ended like that, you are going to make sure that you are building in liability and what have you,” Goss said, “but what that opens is the ability to innovate.”
The major constraint WisDOT placed on contractors is the requirement that highway lanes can only be completely shut down for construction for one weekend per each of the three bridges in the contract, Klein said.
When contractors decide how to demolish the bridges, they must consider how that will affect the older, but still serviceable, bridges beneath, Klein said.
Engineering reports completed in August revealed the need to replace the three Zoo Interchange bridges, and the reports pointed out 101 and 104 are likely to last until the entire interchange can be rebuilt, he said.
During planning meetings for the project before the RFP was issued, engineers brought up the idea of simply detaching the segments of bridge 104 from the interchange when rebuilding the bridge above, Klein said. The 104 bridge can be moved when a new one is put into place above, and then moved back after the project is complete.
Jim Forseth, WisDOT project supervisor, shared that idea with contractors during the Tuesday morning meeting. He also warned contractors about the need to keep all major work on each bridge confined to one weekend between Friday evening and early Monday morning.
“Everybody should be aware,” Forseth said, “that it’s that one weekend closure that we have to make all of this happen.”