GKR were appointed by ISG for the design and construction of a new internal office space with a central atrium.

Works included cantilevers around the entire atrium from the 9th floor up to the top of the 10th floor for access to the windows, soffits and newly erected feature arches.

We cantilevered a lifting beam 8m from the 10th floor so that oversized materials could be raised from the lower ground. A lifting beam was also put in place on the 5th floor to work in unison with the lifting beam on the 10th floor to raise materials up to the 5th floor. Tiered loading platforms serving the 6th, 7th, 8th and 9th floors with a lifting beam fixed to the underside of the 10th floor steels. This allowed for materials to be lifted up to all floor levels that were too large to go up in the lifts.

The access to the project was extremely restricted. The only way to bring material up from the basement loading bay was with the use of a small lift. The maximum length of material that could be raised up was 3m, therefore we used shorter materials as that was all we could raise to the floors via the lifts.

Large birdcages were erected from the 5th floor to the roof so that ceiling works could commence. Another birdcage was erected from the upper ground floor to the underside of the 5th floor for soffit works to be carried out.

The atrium cantilevers had to be designed so that the Arches that were being raised from the 5th level could pass through the sections with minimal disruption to the works. The arches were built on the ground and was raised up, with sections added on as the arch was raised to the top. There were gaps in the cantilever to ensure that the sections could be placed as the arch went up. Additional beam work was installed either side of the arches to allow the sections to be dismantled and re-erected.

Large cantilevered support scaffold was put in place at each end of the atrium to allow a birdcage to be formed, which provided access over the atrium for high level works for the installation of the smoke vents and soffit works.

The loadings on the floor were minimal and each scaffold had to be designed in a way that spread the load to the structural steel.  Beam sections were erected to transfer the loads from the scaffolds into the main strong points of the structure.

Access scaffold was erected for the two feature staircases that were cantilevered at each level, with a main access scaffold to the perimeter. The feature staircase scaffold had to be built so that the heavy-duty platforms could be cantilevered below each flight and landing for the stone install. Tolerances were minimal as the installed needed the platforms to the exact height due to the equipment used being the same size as the stone panels.