[Jeeper]

There are a couple things I've never heard anyone bring up about this building. I know it's not a real proposal, but if it were truly intended on being built, how deep would a foundation for a structure like that need to be? I would imagine it would need to be dozens of floors deep at least. Also, could the ground it would have been constructed on in Chicago even bear the weight of such as immense structure and/or the depth that it's foundation would require? I know it's all speculation, but I'm interested nonetheless.