BG&E provided structural engineering services to the Opus, a mirrored glass building designed by the late architectural legend Dame Zaha Hadid. It consists of two 21 story towers connected at roof level by a six story deep composite sky bridge and six basement levels.

Due to the unusual shape of the building, an innovative construction methodology was developed for the bridge assembly, podium, and temporary platform on the underside of the bridge that enabled facade installation.

The groundbreaking segmental construction sequence for the bridge involved building main trusses and bottom-up external facade grids.

Upon releasing temporary diagonal members, load paths transitioned from temporary to permanent, forming a ‘top-hung’ structure. This innovative approach enabled simultaneous work in various locations across the site, allowed the use of lower-capacity cranes, reduced steel segment tonnage, and minimised construction time and overall construction cost.

Other innovative design outcomes achieved by BG&E include

• Saved three months in construction time by revising the footing design and removing 240 piles beneath the tower footprints.
• An isolation strip was incorporated in the hydrostatic slab to prevent differential settlement stress, reducing reinforcement needs by 30% at the junction between the hydrostatic slab and raft and saving over 60 tonnes.
• Designing flat floor slabs that eliminated the need for edge and cross beams, improving constructability and reducing program time. Podium and link bridge complexities were removed from the critical path by shifting to composite steel construction. Opening three simultaneous construction fronts expedited tower completion.
• The segmentally launched sky bridge didn’t require propping, enabling uninterrupted work on the podium below. Optimised construction sequencing minimised temporary diaphragm actions, ensuring an efficient and buildable structure. Innovative connection details facilitated bottom-up construction with a significant portion hanging in the permanent case.
• Façade installation utilised a temporary steel bridge platform beneath the permanent sky bridge. Innovative construction methods minimised module weights with temporary fixed cantilevered conditions, transitioned to a permanent pin-roller condition, almost halving the platform’s weight, and allowed dismantling with a bridge above it after façade installation.