To turn an underutilized block next to Chicago’s busiest commuter hub into a landmark 52-story building, the design and construction team had to dig deep for creative solutions. While excavating the project, crews had to contend with both an abandoned trolley tunnel and an active brick sewer—both of which were more than 100 years old.
The team had to coordinate removal of the trolley tunnel, which used to pass under the Chicago River and surface above the project site. The demolition contractor was able to remove sections of the old tunnel while the caisson driller followed closely behind, keeping the foundation construction on schedule.