Engineers Sink Nazi U-Boat For Chicago Naval Exhibit 9/20/2004
Engineers working for a Chicago museum knew it would be difficult enough to move a 700-ton Nazi submarine 1,000 ft and squeeze it into a 42-ft-deep, underground exhibit, but they first had to figure out how to shore up a historic, 111-year-old brick structure adjacent to the excavation. And nearby road work gave the engineers little room to breathe as they planned around Chicago Dept. of Transportations $162-million rehab of Lake Shore Drive, now in final punchlisting.
Tim S. Kaye, the museums structural engineer and principal of Chicago-based design firm Halvorson Kaye, calls the teams multifaceted solution of steel sheeting, jet-grout walls, post-tensioned concrete beams, friction micropiles and hand-dug underpinning pits a "catalog" of foundation engineering. "The unusual nature of this project really brought the whole team together," says Kaye, who likens the old-and-new techniques to the artifacts that will occupy the $35-million exhibit, set to open next spring.