treatment of the vertical access

This week I realised that I have been allocating all of my attention to the treatment of the facades of the building and the roof structure. I have finalised the entrance of the building however I have not paid much attention to the heart and mecanics of the building- that is, the central circulation core (spiral ramp system) which runs upwards through the space between the supports of the bridge. My last post spoke about how I am going to treat the facade however I thought I should think about the form of this system. Currently I have designed a standard square shaped ramp.

I conducted some research into some alternatives to this system and this is what I have discovered:

I think at this stage I am most inspired by the last image (above)...