- The Opus building consists of two 20-level towers interconnected at roof level by a 6-storey deep steel sky bridge providing a total of 118.000m2 of built-up area with the top level of the building at 92.94m above the ground floor. The building includes six levels of basement, the deepest ever constructed in the area at the time. Inside the building a theme of leaning columns has been adopted.
- Uneconomical foundation system.
- Presence of numerous edge beams slowing construction time.
- Construction logistics not considered in the design.
BG&E ALTERNATIVE DESIGN
- By taking advantage of the soil higher bearing capacity of what was initially estimated; we were able to revisit the original footing design removing the piles underneath the two tower footprints. As a result we had approx. 5 months saving on construction time schedule.
- We rationalized the design of the foundation under the building’s low-rise area so the use of sacrificial block was avoided.
- During construction, a strip of the hydrostatic slab connecting the low-rise and high-rise foundation was built later to allow the buildings to settle, reducing the development of stress within the structure caused by differential settlements.
- The floors were designed as flat slabs to avoid slab edge beams and cross beams that were present in the original structural concept easing up constructability.
- The steel bridge was designed as a simply supported structure sitting between the two towers easing, up constructability as the towers could be constructed independently from the bridge. In the original design the steel bridge floor plates extended into the tower floor plate.
- Façade installation was done from a temporary steel bridge platform sitting underneath the permanent sky bridge.
- Reduction of the overall construction time
- Improvement on constructability
- Overall construction cost reduction