Higher and Higher: the Ascent to #1 of the Tilt-Up Top Ten
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The Tilt-Up Concrete Association (TCA) has announced multiple changes to its list of tilt-up achievements in the Tilt-Up Top Ten.
The changes made to the Tilt-Up Top Ten in this past cycle are among the most impressive changes in recent years. Four new #1 projects have been listed, including records for Tallest Panel, Largest Floor Area, Largest Footprint, and Recycled Content. While these new records were being set, additional projects made their way onto the lists for Heaviest Panel, Widest Panel, and Tallest Cantilever Panel. What is clear from this much activity is that the challenge for project teams to achieve new marks is compatible with modern program statements and is economically feasible or suitable for the solutions provided.
“The Top 10 list for tilt-up projects was created initially as a way of proving many of the myths surrounding tilt-up wrong as well as recognizing the extreme accomplishments that had been achieved,” states James Baty, TCA’s manager for regulator and technical affairs. ”However, since it became established, the efforts made to achieve a higher mark have been impressive.” Baty continues suggesting that the far more impressive aspect of the Top 10 lists is how buildable they are. “We are in an economy that combines ultra-sensitivity to resources and economics with competitive drive for image and stature or reputation. That these can come together so frequently, as evidenced by the changes in the TCA Top 10, is quite energizing.”
World’s Tallest Tilt-Up Panel Record Shattered
The record for the world’s tallest tilt-up panel was shattered in November when Woodland Tilt-Up of Jupiter, Fla. erected a 111-foot 9-inch tall panel. The record-breaking panel forms part of a nine-story, 600-bed dormitory for Florida International University at their Biscayne Bay Campus located in North Miami, Fla.
A total of 16 of these extremely tall panels mark the living rooms for the dorms. The panel thickness was increased to sixteen inches to accentuate the 13-foot 2-inch wide panels, yet the total weight of each panel, which ranges from 134,000 to 146,000 pounds, remained quite manageable thanks to the large percentage of openings. “It’s a great example of a designer who understands the system using its strengths to accomplish a look,” said Mark Johnson, PE and ESCB of Johnson Structural Group, Inc., who served as the project’s structural engineer.
“The main challenge when reaching these heights is the added boom length and steep angle that greatly reduces the crane’s capacity,” said Gary Fischer, President of Woodland Tilt-Up. “For example, the 146,000-pound panel with an added 30,000 pounds of rigging puts us at the limit with a minimum boom requirement of 230 feet. The crane’s capacity with 230 feet of boom is 187,000 pounds at a 40-foot radius, where a typical boom length of 160 feet gives us a capacity of 234,000 pounds.” Detailed lift analysis and critical lift plans were completed prior to erection to ensure accuracy.
The lifting design, completed by Scott Collins, PE and Engineering Manager for Meadow Burke, incorporated an 8-foot high by 2-foot wide rigging pattern. Bracing was not required as the setting of the panel was performed after all the floors had been placed. “Bracing a panel of this height would not be possible using conventional braces,” said Collins. This approach allowed panel-to-floor connections to be made before releasing the crane. However, this did necessitate a transfer of rigging to additional plumb-setting lift inserts near the top of the panel.
Taking up a new spot on the Top 10 Tallest Tilt-Up Panel list is the Civic Center & City Hall project of Pembroke Pines, Florida. At the corners of this impressive structure stand cores with 89-foot-8-inch-tall panels. These panel heights slide in at No. 6 on the list between the current No. 5 project with panels that are 90 feet tall and the former No. 6 project with panels that are 88 feet 9 inches tall—both located in Boca Raton, Florida. “While these panel heights begin to appear normal in the face of panels over 111 feet, they remain challenging heights to achieve for many project locations, evidenced by the concentration in this state,” states Baty. The current Top 10 List for panel heights has seven projects located in Florida, with only the No. 4 and No. 9 (Texas) and the No. 8 (Arizona) falling outside of the Sunshine State. Panels on this project also contributed to a tie for No. 7 Tallest Cantilever Panel, with a cantilever height (from the top of the footing) of 52 feet 4 inches in some locations.
New Acreages Under Roof
Taking the No. 1 spot in both Largest Floor Area and Largest Footprint is the Daiken Texas Technology Park located in Waller, Texas. Stop the press…this project dwarfs the previous first-place projects at over four million square feet (4,050,196) in footprint and 4,226,749 square feet in total floor area when mezzanines and office floors are included. “The roof is nearly 93 acres in size (92.98), a small farm in parts of the Midwest,” states Baty. “The sheer size of the panels being erected on this project is every bit as impressive as the total building area, even though both height and width fall outside of the Top 10 list.” Not to be outdone by projects with massive panels, the tallest panel on this project came in at 59 feet 7 inches tall, and the widest panel on the project was an impressive 61 feet 3 inches.
Topping Out with Sustainability
Proving that Top 10 challenges can offer sustainability to a project even beyond the known aspects of thermal performance, resiliency, and material efficiency, a new No. 1 for Recycled Concrete Content has been recorded. The Crossroads Commerce Park 1-4 in Denver, Colorado nearly doubles the previous No. 1 (3,692 tons) with a total recycled concrete content of 6,673 tons. The project itself only enclosed 357,692 square feet but did so with a specific focus on setting a new standard for making the most of recaptured and recycled materials.
More Top 10 Movers
Rounding out the recent changes to the Top 10 lists are panel achievements for Heaviest Panel and Widest Panel. “These are equally impressive when considering the panel configurations and the creativity delivered on the projects,” offers Baty. “It is easiest to think of panels as large, opaque masses of concrete and steel. Perhaps this is yet the case today for the clear majority of panels, but we continue to see such dramatic shapes and configurations designed and constructed that no longer can any general description apply.”
This is certainly the case with the new No. 8 widest panel constructed for the “All Aboard Florida Fort Lauderdale Station” project in Fort Lauderdale, Florida. Structural truss panels of 70 feet 1 inch were formed and erected to establish the architectural appeal of this project and provide long-span structural efficiency for the train station. These panels slipped in between the No. 7 panel width of 70 feet 2 inches and the former No. 9 panel with a width of 70 feet.
Keeping up the trend, the addition to the Top 10 Heaviest Panels rounds out the top five all over 300,000 pounds. The Northgate Distribution Center – Buildings 1 & 2 project in Las Vegas, Nevada produced the new No. 5 with a weight of 309,000 pounds. “This is ‘below the hook’ weight,” states Baty, “which the experienced tilt-up contractor recognizes is an even greater challenge on the erection team when adding up the rigging required for such massive panels.” The project proves that heaviest panels are not just rectangular chunks of concrete and steel—these panels featured large-span openings as well as large punched openings, with integrally cast pilaster features. Whereas common pilaster is cast as an integral column to the panel thickness, these pilasters were formed as U-shaped extensions of the panels to achieve the depth at the façade required by the design while remaining as efficient as possible with the weight.