In Miami, successfully assembling an ‘orange’
Skanska is building the iconic Patricia and Phillip Frost Museum of Science in Miami. The planetarium is in the foreground.
Unlike most planetariums, which are constructed inside an existing building that serves as a structural framework, the planetarium adjacent to Miami’s Patricia and Phillip Frost Museum of Science museum, will have a concrete orb that will support itself — which made constructing it a logistical challenge.
To create this very unusual planetarium, the Skanska USA team had to assemble 32 concave precast concrete orange-peel-like pieces – weighing nealy 23,000 kg per panel – to form a full-dome planetarium. The operation required 24-hour-a-day/seven-day-a-week work over two-and-a-half weeks to precisely place and connect the segments.
The team had been planning this extremely challenging operation for months before. The operation began with erecting a massive, 15.25-m-tall centre shoring tower and setting a precast dome cap, which was 100% welded off before any of the ‘orange-peel’ segments could be rigged and lifted into place. The shoring tower was necessary as the segments couldn’t support themselves until all 32 of them were in position.
To maneuver the pieces, The Skanska team brought in a specialised 550-ton hydraulic crane with a superlift.
Once the centre pieces were in place, the Skanska team installed the orange-peel perimeter segments opposite one another in a counter-clockwise rotation to avoid lateral load on the dome cap. To maneuver the pieces, they brought in a specialised 550-ton hydraulic crane with a superlift. This sequence required erecting the panels during the day and connecting the panels at night to be ready to erect new panels in morning and maintain schedule.
The team erected panels during the day and connected the panels at night so they could be ready to erect new panels in morning and maintain schedule.
The team paid close attention to safety during this critical and not-so-traditional precast operation. The shoring tower was an engineered system that was inspected daily before work could commence, as it served double duty as a working platform and shoring tower. The planetarium was barricaded off at all times to only allow specially trained and authorised personnel to enter.This day and night operation had no safety incidents.