Strategy:
I chose a metal frame structural system for my building ,since it is a complex organic shape, and for lightweight properties of steel. That would also best support longer spans, since large, clear spaces, like in atriums and display areas. Port Blair, where my building is located, does not commonly use a wood structure, and concrete would become too heavy. Hence, a steel frame made most sense. Since the building has an irregular shape, I also using cross beams at the ends to tie and secure the grid, instead of using curved beams. Initial sketch:
Sizes:
I decided the sizes based on the clear spans that might be needed. For the columns, I used a 12x40 steel i- channel. The design intent is to have slender columns and then use them as a feature in the interiors, like perhaps a signage placeholder, or clad it with an accent facing.
For the beams, I used a 12x26 sized steel I-beam. This combination of column and steel resulted in clear spans of up to 50ft.
Challenges:
- The shape of the building makes the structural system complex, but I kept it simple with a regular grid. Many of the exterior bits of the building are currently overhangs/cantilevers, which is because I did not use curved beams.
- Rotating floor plates, i.e., inconsistent floor plate from floor to floor; due to this, I had to change/add columns and beams and adjust several times.
- Especially tough were areas like the atriums, since they were large spans that need to be clear.
- The sloped roof posed more issues. The beams had to be made sloping to support the roof. That also meant irregular column heights. I could not copy/monitor the roof onto the structural model since I would have to then delete it from the architecture model to avoid duplication, and this would further complicate things because the arch model walls are attached to the roof.
- Elevator shafts were other areas I have to exercise caution, so that beams do not pass through them.
Images from the model:
The following are the reflected ceiling plans, where the visibility graphics settings have used to make the columns pink and beams green for easy identification.
Typical RCP:
View of the structural model:
Interior views of the coordinated model:
