I build the iCorp Tower because Chris of TexLUG-SA (Texas LEGO User Group – San Antonio Chapter) was "whining" that we (TexLUG) didn't have any tall LEGO skyscrapers like other LUGs.
The thick base on the 32x32 baseplate has a grid of long technic bricks in it, locked together by a layer of plate and then a layer of tile. In the center of each of the three black 3x3 stud support columns is a technic beam, pined into the thick base and into the cantilever support technic bricks and beams in the first 2 floors of biconvex section. All the higher biconvex floor's sections stack on that.
When I first showed this MOC I wasn't happy with the color of "band"/"stripe" at the top. I used dark orange, but I had tried yellow, orange, and red. Steve (TexLUG Austin) suggested trans "dark" something, I am happy he did!
I found that "stressed" 48 1x2 bricks(or plates) makes a biconvex shape that has a radius of 31 studs, ie. it fits inside a 32x32 baseplate's footprint. The "stressed bricks" technique lets you build curved walls, for more info:
When I build this building I didn't know that there was a real building that looked like this: