VAA was Structural Engineer of Record for the design of a three-level Target store and parking facility featuring a glass atrium on a congested urban site at the corners of Clark and Roosevelt streets in Chicago, Illinois. The integrated facility includes 155,000 SF of retail space, 28,000 SF of stockroom and 370 parking spaces. The tight, urban site is bounded by elevated roadways on two sides and a major rail corridor on a third side. Deep foundations were coordinated with a series of large tunnels that run underground, a fiber optic duct bank, a major sewer interceptor and a buried dock that was discovered during pile driving.
The structural design incorporated both composite steel framing and post-tensioned concrete beams and slabs to minimize cost and compress the construction schedule. Post-tensioned concrete was used for the parking ramp. Structural steel was used for the remainder of the retail space. Long span transfer girders up to 90’ long were used for the dock and truck entry and exit routes, eliminating columns in order to maintain the open drive lanes under the building. Spans of 60’ or more were used throughout the structure to provide the most efficient parking layout. VAA performed vibration studies to predict and limit vibration due to vehicles and adjacent train traffic.
The project also included an independent post-tensioned parking structure immediately adjacent to the Target store. The adjacent parking ramp was designed with capacity for a two-story vertical expansion.
