For about 50 years, many developers and design teams—salivating over the best-located piece of real estate left in the heart of Chicago—have tried unsuccessfully to come up with an economically viable project for the sliver of a site, hemmed in by active railroad tracks, viaducts, a building and the Chicago River. But thanks to a core- supported design and an air-rights agreement with Amtrak, foundation work is underway for a two-acre development that includes a 54-story office building.
The structural design solved the problem of the limited touchdown area for the tower footprint, but it created many others challenges for the cramped site, which Amtrak, the city and the developer collectively own. There is only one single-lane access road. Trucks have to drive in, unload and back out. There is no laydown area or even room for a crawler crane. And rail traffic limits work hours on some foundations.