Synthesis on Cost-Effectiveness of Extradosed Bridges

015987819483087302016PDFTech ReportFHWA/TX-12/0-6729-1Project 0-6729Cable stayed bridgesGirder bridgesLiterature reviewsStatistical analysisCost effectivenessBest practicesCase studiesInterviewingExtradosed bridgesCost dataExpertsBridges and other structuresDesignHighwaysAsiaEuropeNorth AmericaSouth AmericaAfricaTexas State University--San MarcosHu, JiongKim, Yoo JaeLee, Soon-JaeTexas State University--San MarcosTexas. Dept. of Transportation. Research and Technology Implementation OfficeUnited States. Federal Highway AdministrationUS Transportation CollectionAn extradosed bridge is a unique bridge type that utilizes both prestressed girder bridge and cable-stayed bridge concepts. Since the concept of an extradosed bridge is still relatively new, there is no clear definition and specification of the type of bridge. Also, due to the unique characteristics of an extradosed bridge, it is likely to initially cost more than a conventional girder bridge but less expensive compared to a cable-stayed bridge. This synthesis study identified and collected information on 120 extradosed bridges from Asia, Europe, North America, South America and Africa through a comprehensive literature review of over 350 technical papers, reports, and websites. Cost information on 58 extradosed bridges and bridge selection reasons for 47 extradosed bridges were collected and summarized. Over 100 individuals with experience in the design and/or construction of extradosed bridges were contacted. Telephone and email interviews of eight experts in extradosed bridges (three from Asia, three from Europe, and two from North America) were conducted. A statistical analysis was conducted to summarize general configurations, bridge selections, constructions, and costs of extradosed bridges. Four case studies regarding extradosed bridge selection were also included in the report. In addition, this study summarized the advantages and disadvantages of utilizing extradosed bridges, best practices, and existing methodologies. While there is a variety of advantages and disadvantages comparing extradosed bridges to girder bridges and cable-stayed bridges, the team identified aesthetic (signature bridge and landmark structure), underneath (navigation/vehicular) clearance and higher restriction, and construction and structure considerations were identified as top reasons for selecting extradosed bridges over other alternatives. A bridge selection process specifying considerations for determining how and when an extradosed bridge is cost-effective and in the best interest of the public was also recommended.75