ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/297033
A critical downtown artery, Wacker Drive is home to several buildings that define Chicago's iconic skyline. The street is actually a multi-level viaduct structure with upper- and lower-level traffic that jogs along the Chicago River and borders the central business district. The Willis Tower (formerly the Sears Tower), the Civic Opera House, and the Chicago Mercantile Exchange are among those that claim a prestigious Wacker Drive address. An estimated 60,000 vehicles use the drive daily, along with 225,000 pedestrians and vehicles on the associated cross streets. T h e n o r t h - s o u t h l e g o f t h e v i a d u c t i s b e i n g r e c o n s t r u c t e d t o m o d e r n i z e t h e u p p e r a n d l o w e r l e v e l s , p r o v i d i n g a s a f e r, m o r e - e f f i c i e n t r o a d w a y f o r m o t o r i s t s a n d p e d e s t r i a n s . T h e r e c o n s t r u c t e d v i a d u c t i s 2 9 0 0 ft long and 140 ft wide, equaling more than nine acres. This project i s a n e x c e p t i o n a l e x a m p l e o f c o m p l e x u r b a n r e c o n s t r u c t i o n w i t h n o t a b l e a c c o m p l i s h m e n t s i n structural engineering, stakeholder c o m m u n i c a t i o n , m a i n t e n a n c e o f traffic, and infrastructure security. Substructure and Geometry Details T h e u p p e r d e c k i s s u p p o r t e d b y i n d i v i d u a l c o l u m n s l o c a t e d t o accommodate the main travel lanes, service lanes, a median, and numerous building entrances on Lower Wacker Drive. The 3-ft-diameter columns are spaced roughly at 32 ft on center in the longitudinal direction. The transverse spacing varies to accommodate the different constraints as shown in the typical section. The columns at the expansion joints utilize a hammerhead cap in order to support bearing lines for profile WACKER DRIVE VIADUCT / RANDOLPH ST. TO MONROE ST.—CHICAGO, ILLINOIS BRIDGE DESIGN ENGINEER: Alfred Benesch and Company, Chicago, Ill. CONSTRUCTION ENGINEER: Parsons Brinckerhoff, Chicago, Ill. PROGRAM MANAGEMENT ENGINEER: TranSystems Corp, Schaumburg, Ill. PRIME CONTRACTOR: McHugh Construction, Chicago, Ill. READy-MIx CONCRETE SUPPLIER: Ozinga Concrete, Mokena, Ill. POST-TENSIONING CONTRACTOR: DYWIDAG-Systems International USA Inc., Bolingbrook, Ill. Reconstructing Chicago's Prized Wacker Drive by Andrew Keaschall and Hossam Abdou, Alfred Benesch and Company, and Johnny Morcos, Chicago Department of Transportation Typical cross section through the viaduct. Figure: Chicago Department of Transportation. 18 | ASPIRE , Fall 2012 P R O J E C T AspireBook_Fall12.indb 18 9/18/12 8:58 AM