Short Week for Holidays; 185+ Precast Pieces in Place

 

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June in Knoxville has had the most rainfall on record, but when the rain stops the precast crews are eager to push forward.

TDOT rules for holiday traffic have also impacted movement of  permitted “heavy loads.” This required early staging of precast to have materials onsite to complete the day before the 4th of July and to have stock available for an early start on Monday.

On the north end of the project, backfill for retaining wall # 1 progressed with the use of dense graded aggregate, as most soils in the area were too wet to use for structural fill. Concrete crews progressed with the first of two pours for retaining wall # 3. Crews also prepared for our first slab on grade for the parking deck. This small pour is required due to limited access for form removal after precast is erected.

Caisson crews were busy at the southern end of the project, but were delayed by rain and pentacle rock, which was not stable enough to support our foundations. Deeper than usual drilled piers were required.

The Precast Puzzle Takes Shape

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To date, more than 125 pieces of precast concrete structure stands in the air. Crews worked long hours this week. We are now able to see the upper level retail floor slab elevation and parking deck below.

On the far north end of the project, the final pour of retaining wall # 1 was completed. As crew completed this pour, grading crews we busy installing foundation drains and backfilling previous poured sections of this wall. Earthwork for the future slab on grade area of the parking deck was also ongoing this week.

On the southern end of the project, foundations for retaining wall # 3 were excavated, reinforcing steel was installed/inspected and the concrete pour was completed. Progress was also made with the installation of drilled caissons and pier caps that will serve as the foundation of the southern retail center and parking deck.

Heavy thunderstorms were numerous and rain total exceeded 2 1/2 inches.

Going Vertical in Knoxville

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This week, we reached our milestone date for vertical precast erection at the northern section of the parking deck retail center. Due to the unstable soils in areas of the project, this process started with the installation of crane pads to support the heavy load of a 250 ton capacity crane as well as trucks hauling in as much as 70,000 pound loads. With our working platform in place, the first of many loads of precast arrived.

Crews moved forward column by column until we were ready to set the first precast girder and “Double T” panel that creates the level parking slab.

Retaining wall construction also moved forward at wall # 1 with our fourth major pour. This will leave only one more large pour scheduled for early next week. On the south end of the project, caisson crews progressed with drilled piers. Our grading crew worked on roadway fill as well as preparation for our next two retaining walls.

 

Team Comes Together For Lunch

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With almost a 20-acre job site, crews are working in all areas performing tasks specific for their trade. Today the entire team gathered to share a barbeque lunch and a little shade in the hot June weather in Knoxville. Thanks to Volvo Rents and well as the onsite office team for their efforts.

Out in the field, progress was made with another concrete pour at retaining wall 1. Other crews were busy with rebar installation and forming for the fourth pour which will take place early next week.

At the Northern Retail Center, grading of the building pad moved forward as existing tunnels from the Fulton Bellow factory were also opened and filled. At the center of the site, crews poured loading bearing retaining walls. On the southern end of the project, caisson crews moved forward with drill pier installation. Site grading and excavation for the foundation of retaining wall 2 and 3 also progressed.

 

Specialized Foundation Crews Back Onsite

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Work at University Commons this week included the return of several specialized contractors. At the center area of the project, soils were tested and found to be unsuitable for footing installation. Geopier crews returned for installation of a support system for the settlement sensitive load bearing footings and the wall that will support precast structures. With that work complete, footing installation resumed in that area.

At the southern end of the project, caisson installation moved forward after the release of permit. On the northern end, retaining wall footings were completed and our first wall pour was made. Crews also progressed with rebar and form installation for future wall pours.

Civil work included utility installation with the setting of multiple large water quality filtration units as well as building pad fill and grading.

 

Concrete Pour Ongoing at All Levels

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Concrete crews were busy in several locations, including  the northern end of the project. Here, footings were completed at site retaining wall one, our next to last pour. As footings were poured on one end of the wall, other crews were forming and pouring the first wall section.

At the center section of the site, pier cap installation was also ongoing for the parking deck and a section of shops. On the south end of the project, excavation was ongoing for installation of storm sewer water quality unit,s which will monitor and filter stormwater before it enters the local streams. The first bridge abutment footing pour was also completed this week.

Birth of a Concrete Retaining Wall

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Because of the unique aspects of the old Fulton Bellows site, the University Commons Project will have several retaining walls.

Past progress photos have shown installation of the footings for one of these walls within the building footprint. This week, the crew worked vertical with their reinforcing steel and forms for a cast in place concrete wall that will be poured later this afternoon.

In other areas of the project, footings are being poured for site retaining wall # 1 as well as caisson pier caps at the northern retail site. Smaller footings and parking deck retaining work is also ongoing.

Pier Cap Installation–New Critical Path Activity

Knoxville Collage 4-19-13With the completion of caissons on the northern retail center, crews are busy with pier cap installation in the area. These caps will be the foundations for the installation of the precast columns scheduled to arrive in about a month.

This operation begins with the excavation of the area around the drilled caisson. A “mud slab” is then poured to allow an all-weather working surface. Rebar crews then move into install the reinforcing steel for the pier cap.  Final forming is installed for the support of anchor bolts and precast dowels. With work completed, quality control inspectors check for size, count and location of imbeds. With approval, the concrete truck are released to pour.

Elsewhere on the project, grading for retaining wall footings move forward. On the southern retail center,  a partial release of this area has allowed caisson crews to proceed.

 

Site Utility Work On the Move

Knoxville Collage 1Knoxville Collage 2With the release of another portion of the site grading permit, utility crews were quick to start installation of the storm sewer main. The caisson crew neared completion of the drill piers for the northern retail center with more than 180 poured to date. Less than 10 remain, and they are scheduled to be pour early next week. Caissons for the southern retail center will also begin next week.

UT archaeologists completed their additional ground penetrating radar (GPR) study at the request of TVA. A second crew arrived onsite this week for the installation of pier caps. Operations are now ongoing on both upper and lower elevations.

Demo of the southern elevated concrete slab will be completed this week. This material is being ground and recycled for structural fill.

 

New Operations Begin at University Commons Site

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With 155 drilled piers poured and only 39 remaining on the north end of the project, the next phase of operations in that area begin.

A special engineered support system called Geopiers was installed for retaining wall # 1 this week. These piers are constructed by applying direct vertical ramming energy to densely compact successive thin lifts of crushed rock.

While on the upper level of the building pad, crews excavated around the drilled and poured concrete piers  for future pier caps. These pier caps will support columns and shear walls for the parking deck and second  level retail centers.