I happened to be near ST a couple of nights ago and thought I would see what was going on.
Whoever posted the blueprints a few pages back did a great thing. Very illuminating. The structure is remarkably complex (even more so than it appears from the outside) with striking differences between sections.
At the site now, one can see the lower core with its nine-part structure, complete to level 11. All the steel is specially fabricated; no building using standard beams to save money.
Up close, the core is just huge - it has a horizontal area as big as most completed buildings, and that is only the core! ST is really a monster.
Another weird thing about this building, is the arrangement of the cranes; there are four now, all affixed on stands to the side of the core. I have never seen this arrangement on any building before. Perhaps they plan to jack the crane bases up as the building rises, since otherwise, the bottom of the crane would obstruct the outer part of each floor that has to be built around the core.
ST backed by Jin Mao and WFC.
closeup of the cranes
another shot
different angle
the third "brother" taking shape