In the area where a 60-foot section of wall containing about 30 tons of concrete plunged June 11 from downtown Topeka's Polk-Quincy Viaduct, workers are cutting away the remaining walls and carefully lowering them down to the street.
The Kansas Department of Transportation will replace about 2,200 feet of wall — amounting to about 1,100 feet on both sides — in the area involved, said Burt Morey, deputy secretary and state transportation engineer for KDOT.
About 50 feet was removed Thursday, which was when work began, Morey said.
"They're ramping up to get about 100, 150 feet a day," he said. "It should take about 20 days. It should be done by the third week in July."
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Workers wore hard hats and fluorescent vests Friday at the scene, where Morey said each eight- to 10-foot section of wall being removed weighed about five tons.
"Safety's our top priority and we want to make sure this gets done properly," said KDOT Secretary Julie Lorenz.
She acknowledged that the work poses an inconvenience in terms of traffic, and said she appreciates everyone's patience.
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Morey and Lorenz spoke to reporters Friday at the scene where the deterioration of steel connecting a 60-foot section of concrete barrier wall to the aging viaduct caused that section of wall on June 11 to plunge to the ground.
KDOT officials felt concerned enough about the deterioration of the reinforcing steel holding that wall to the deck that they decided to "take it all off," Morey said June 14.
The temporary barrier being put in to replace the walls being removed will remain part of the viaduct until the viaduct is replaced in about four and a half years, Morey said.
The work that began Thursday involves boring a hole through each section of concrete wall, running chains through it, then using an excavator to lower each section to a forklift below. The pieces are then stockpiled and hauled off, he said.
The distance from the bridge deck to the street is 25 feet, said Steve Hale, communications director for KDOT.
It remained unclear Friday how much the work would cost, Morey said.
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The wall collapse came at a time when traffic was narrowed to one lane going each way on the viaduct so maintenance work could be done to keep it viable until it is replaced.
KDOT has kept the viaduct open, saying it remains structurally safe, while continuing to allow traffic for one lane in both directions.
"The one-lane configuration is working," Morey said Friday.
KDOT has seen "a little bit of backup" during the morning and evening rush hours but isn't seeing anything that suggests it should do anything different traffic-wise, he said.
The city of Topeka currently has S.W. 2nd Street blocked off below the viaduct and is also blocking off that street's intersections with S. Kansas Avenue, S.W. Jackson and Van Buren.
KDOT plans to carry out the wall replacement work in a manner that will allow for Kansas Avenue to be reopened first, then Jackson, then Van Buren, then the sections of S.W. 2nd Street in between, Morey said.
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KDOT no longer builds bridges using the steel connector design that was used on the Polk-Quincy Viaduct in 1963.
The agency announced June 16 it would inspect all its bridges statewide that have barriers and railings similar in design to the Polk-Quincy Viaduct.
KDOT has identified about 280 such bridges, Morey said Friday.
One crew started inspecting those last week and has done about 35 so far, he said.
Two more crews will start work next week, and inspections are expected to be complete by the end of July, Morey said.
So far, he said, "We haven't found anything that's alarming to us."
Tim Hrenchir can be reached at threnchir@gannett.com or 785-213-5934.