Tilt-up has reached new heights! The world’s tallest tilt-up panels were erected this past winter at the Florida International University Biscayne Bay Campus near Miami. The panels stood 111 feet, 9 inches tall and were constructed as part of a nine-story, 600-bed dormitory. Construction required a total of 16 extremely tall panels to form the living rooms within the dormitory, with each panel measuring 13 feet, 2 inches wide, 16 inches thick, and weighing 134,000 to 146,000 pounds.
The project came to Meadow Burke about two years ago when Woodland Construction Co. of Jupiter, Fla., approached the tilt-up engineering team with a nine-story concept panel. At first glance, it seemed that this was pushing the limitations of what was achievable in tilt-up. But an increase in the thickness of the panel to 16 inches made it possible to come up with a preliminary detail using a conventional four-high rigging pattern and requiring reinforcing using #9 rebars.
Meanwhile, designers worked on an efficient plan for an eight-high lift. The lift included using 16 inserts which were cast into the face of the panel and anchored with Meadow Burke’s Super-Lift III Face and Edge Lift Anchors and Clutch System. The inserts were placed in a combination of eight rows and two columns to be able to lift and rotate the panel.
Super-Lift III face lift inserts were used to provide a safe and secure panel lift, while the Super-Lift III Edge lift inserts were used for final setting with the panels in a plumb position. Other lifting products supplied for the job included 8-inch steel strongbacks, which were used for the tall panels to resist bending moments, as well as B-75 bracing inserts.
By late summer 2015, the project was a go and engineering began to further tackle the lifting design. While the weight of each nine-story panel was not uncommon compared to the typical tilt-up panel, the extreme height of the panel presented several lifting challenges, including potentially exceeding the crane’s lifting capacity. Rigging was critical in solving that challenge so that the crane worked with the maximum reach of the boom. Last minute adjustments to sling lengths were required when lifting the first panel.
Besides the nine-story-tall panels, there were three other types of panels used on this project. These additional panels were divided into four, three, and two stories attached to the structural steel building in a stacked arrangement on top of each other, with the four-story panels at the bottom, the three-story panels in the middle, and the two-story panels at the top. In all, there were 106 additional panels besides the 16 nine-story tall panels, for a total of 122 panels for the entire project.
With the challenge of five-story panels stacked on top of four-story panels, tilt-up engineer Elizabeth St. John took on the engineering for the standard panels while Meadow Burke’s Engineering Manager, Scott Collins, took on the engineering for the unstacked tall panels.
As the design was being worked on, the eight-high lifting analysis was also ready for beta testing. After several updates from the programmers, Collins was confident that it was suitable for the panels and that it would reduce some of the risk that would have been taken with a four-high lift.
The final lifting design used an eight-high by two-wide rigging pattern. During lifting, the contractor had to transfer the load to additional plumb-setting lift inserts near the top of the panel. Bracing the panels after lifting was not required since the setting of the panel was completed after all the floors had been placed. Despite being designed for 185 mph wind loads, since the panels were attached to the steel building frame at each floor, minimal steel reinforcement was needed for the final in-place loads.
The Meadow Burke tilt-up inserts for the project were supplied by leading distributor HD Supply White Cap of Pompano, Fla.
Amidst the complexities and challenges that came with the design, the results proved to be a worthy concept. The project now holds the record for the world’s tallest tilt-up panel as recorded by the Tilt-Up Concrete Association. With the ingenuity of the teams involved, this was another successful tilt project to add to the books for Meadow Burke and Woodland.