Blog: City Blog

1st Concrete Deck Poured for New Jackson Avenue Ramps; 2nd Pour Anticipated This Week

Visible, dramatic progress is being made on the Jackson Avenue Ramp Replacement Project. But the nearly $7 million project will take a few months longer than initially estimated.

"We know that the Old City businesses on Jackson Avenue are feeling the effects, and we're wanting to get this done as quickly as possible," Downtown Coordinator Rick Emmett said. "But at the same time, this is a once-in-a-century opportunity to strengthen building foundations and ramp supports, ensure modern safety guidelines and take the necessary steps to make sure this new bridge holds up for another 100 years, just as the original 1920 bridge did."

The project team headed by Bell and Associates Construction has poured concrete for the first half of the Jackson Avenue ramp on the west side of Gay Street. This week, they anticipate pouring concrete on half of the east ramp.

Bell and Associates crews poured concrete for the first half of the Jackson Avenue ramp on the west side of Gay Street.

Bell and Associates crews poured concrete for the first half of the Jackson Avenue ramp on the west side of Gay Street.

The concrete is poured over stay-in-place deck forms and two layers of epoxy coated rebar using a bridge deck screed (pictured below). After the pour, brown burlap sheets are saturated and cover the new deck to allow for a proper curing environment.

Concrete for part of the west ramp was poured into this structure for added strength.

Concrete for part of the west ramp was poured into this structure for added strength.

A burlap covering protected the new concrete poured for the west ramp.

Retaining wall supports will be constructed before the last decks can be built. Then sidewalks will be added, and then - one of the last steps - the historic red pavers will be placed back onto the top of the ramps.

Knoxville City Council at its Sept. 8, 2020 meeting voted unanimously to authorize a contract amendment, increasing the cost by about $500,000 in additional federal transportation funds and extending the completion date to Dec. 8, 2020. (Including design work and right-of-way acquisition, the project's total cost is about $8.7 million. The City's investment is about $270,000.)

Problems arose that could not be foreseen below the 100-year-old elevated street and ramps.

Discovered during construction, there were conflicts with buried communications and electric infrastructure. So the network of micropiles was redesigned.

Existing soils were to be used as backfill around new foundations and behind retaining walls. But the soil was found to be unsuitable, and bricks on site were in such poor condition that they could not be used as backfill, either. They would not bear weight properly and meet modern safety requirements, so that material is being removed and appropriate backfill brought in.

Finally, during excavation for the southwest retaining wall, it was discovered that the Armature Building foundation needed to be further stabilized.

"Gay Street was elevated a century ago by a building floor or two, depending on the spot," Engineering Director Harold Cannon said. "Anytime you work in an old downtown area, you're going to run into surprises that aren't plotted on any maps. That's what's happened here: These issues could not have been foreseen until crews were down into the trenches, so to speak.

"We thank Old City residents, workers and business owners for their patience. When this project is completed, we will have new ramps that are safe and attractive, using the repurposed pavers. That was aesthetically important to many people, and it's important to the City that the new ramps look like the iconic originals."

Posted by evreeland On 10 September, 2020 at 12:19 PM