Formwork Innovation

An essential part of the architectural vision for the new U.S Courthouse in San Diego is the 45x11-ft. exposed concrete elevator core running the full 17-story height and more.

The single form panel for the long exterior architectural face of the core weighed 15,000 lbs., requiring the use of a spreader beam to maintain integrity of the form during hoisting.

Three additional platforms trailed the main work platforms, providing access to the wall to remove rustication strips and tie hole cones, and to allow retrieval of the attachment hardware.

The overall height of the work platform assemblies was 30 ft.; when the tallest wall form panels were installed, the overall height of the formwork system stretched to nearly 55 ft.

For the interior formwork, a 43x8-ft. truss platform was prefabricated in Atlas’ San Diego yard and delivered to the site.

On each side of the truss platform were flipper pales (like keys or a locking mechanism) that supported the platform by fitting into tapered void pockets that had been cast into the wall during the previous lift. Also note the hinged platform section.

A worker stands on the finished floor outside the elevator core. Note the access stairs coming up the core shaft and the folded down hinged platform section.

When it came time to install the steel columns, the hinging platforms were swung up out of the way, providing crane access to below.

A system of temporary stairs and ladders provided workers with access to the working platforms as the work progressed up.

To accommodate the different elevations between the platform and form panels, a system of sliding strongback channels and screwjack assemblies was developed.

To form the wider cantilevered section, the return wall panels were swapped for wider panels.

The formwork for the cantilevered section was supported by a shoring platform, comprised of two 36-in.-deep castellated beams.

With the form panels and three platforms, the entire formwork system stretched to nearly 55 ft.

Structural steel erection lagged behind the core by as much as three floors.

The core continues its ascension.

Platform assemblies were separated in the middle for repositioning.

The pattern of tie holes and rustications was carefully defined by the architect.

The platforms are being removed for the last time.

An essential element of the new U.S Courthouse in San Diego is the 45x11-ft. exposed concrete elevator core running the full 17-story height.

A system of temporary stairs and ladders provided workers with access to the working platforms as the work progressed up.

Close X