City: Chicago
State: Illinois
Owner: Museum of Science and Industry
General Contractor: W.E. O’Neil Construction Company

Project Description:
The Museum of Science and Industry U-505 Submarine Relocation project required the construction of an underground reinforced concrete vault shoring (37 ft deep) and underpinning of the existing museum footings for construction of a new elevator and stairwell area.

Schnabel designed and installed the shoring and 21 micropiles approximately 65 ft long to support the existing structure.  The micropiles consisted of a 9-5/8” diameter by 0.545-inch thick permanent casing extending into the stiff clay with a #20 bar extending the full length into the Chicago hardpan.  To minimize interference with future building walls, the micropiles were drilled at a slight batter underneath the existing footing.  Reinforced concrete micropile caps were placed under the existing footings to permanently support the building load.