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/306186
T h e M i a m i I n t e r m o d a l C e n t e r — Earlington Heights Connector (MIC- EHC) is located in the Greater Miami area east of the Miami International Airport (MIA). The MIC is a regional transportation hub of the Florida Department of Transportation (FDOT) that is now under construction. The facility will connect local and regional t r a n s p o r t a t i o n n e t w o r k s t o M I A , including Tri-Rail, Amtrak, Intercity bus, Metrobus, taxis, and tour buses to MIA. The MIC will also house the airport's rental car facilities. The MIC- EHC will provide a light rail connection to a new MIC Metrorail Station via a 2 . 4 - m i l e - l o n g e l e v a t e d g u i d e w a y from the existing Earlington Heights Metrorail Station located at State Road (SR) 112 and NW 22nd Avenue. The MIC Metrorail Station and MIA will be linked with an automated people mover owned by MIA. The MIC-EHC will become part of the Metrorail system Orange Line in Dade County and will be owned and maintained by Miami-Dade Transit (MDT). Project Requirements The MIC-EHC has a variety of existing and future site conditions that require special span arrangements and structure types along its elevated 2.4-mile alignment. Structures in the vicinity of the MIC Metrorail Station had guideway span lengths limited to 130 ft to match the bus spacing at ground level. The South Florida Railroad Corridor (SFRC) required a three-span continuous structure with a minimum span length of 180 ft to span over the railroad tracks. At the Miami River, a three-span continuous structure with a minimum vertical clearance of 40 ft from mean high water was required, and with columns and footings of the guideway located clear of the river shoreline. A five-span continuous structure with a main span of 256 ft was required to span over the existing SR 112 eastbound and westbound roadways and the future Miami Dade Expressway (MDX) SR 112 project. To meet these varied requirements, the MIC-EHC designers utilized several superstructure configurations, including 72-in.-deep precast, prestressed concrete Florida U-beams; precast, post-tensioned segmental concrete box girders; and conventionally reinforced 30-in.-deep, cast-in-place concrete slabs. Structures overview Cast-in-place concrete slab bridges, 30-in.-deep, are used at the connection to the Earlington Heights Station. There are a total of 13 spans or 571 linear ft of guideway. Span lengths vary from 41 profile MIAMI INTERMODAL CENTER—EARLINGTON HEIGHTS CONNECTOR / MIAMI, FLORIDA BRIDGE DESIGN ENGINEER: URS Corporation, Tampa, Fla. PRIME CoNTRACToR: Odebrecht Construction Inc.—Tower-OHL Group—Community Asphalt Corp.-OHL Group, Joint venture, Miami, Fla. PRECASTER: u-BEAMS: Standard Concrete Products, Tampa, Fla., a PCI-certified producer SEGMENT PRECASTER AND ERECToR: Rizzani de Eccher USA, Bay Harbor Islands, Fla. PIER SHELL REDESIGN: McNary Bergeron & Associates, Broomfield, Colo. SEGMENTAL BRIDGES PoST-TENSIoNING SuPPLIER: DyWIDAG Systems International-USA Inc., Bolingbrook, Ill. SEGMENTAL BRIDGES PoST-TENSIoNING CoNTRACToR: Rizzani de Eccher USA, Bay Harbor Islands, Fla. by Velvet Bridges, URS Corporation The Miami Intermodal Center— Earlington Heights Connector ConneCting the Dots Typical section through the dual-track segmental box girder. Drawing: URS Corporation. 26 | ASPIRE , Summer 2011 Book_Sum11.indb 26 7/1/11 9:59 AM