Wide Flange Decked Girders
Wide Flange Decked Girders

The WSDOT, WFDG and WFTDG series girders are the newest girder cross sections developed by Washington State. These versatile girders combine the longer span capacity of the WF girder with the reduced field work advantages of the Deck Bulb Tee girders. The bottom flange of these girders exactly matches the standard WF girder bottom flange, while the top flange of these girders come in two configurations that match 3” and 6” decks of the Deck Bulb Tees. TDG girders have the 3” integrated deck which can span up to 8’ wide, while the DG series have a full 6” thick integrated deck which can span up to 10’ wide.

The WFTDG series includes all the depths of the standard WF girders. The WF36TDG is 36” deep and can span from between 100’ – 120’ long (depending on the spacing). The longest spans are to be found using the WF83TDG which can reach 200’ – 215’. The WFDG girders are 3” taller than the standard girders due to the 6” deck. The WF39DG spans from between 100’ – 115’ while the WF86DG can span 160’ - 195’. There are many possibilities for customization including: tapering widths, curved decks, cross slope and camber compensation flange thickening. The top surface can be finished as a driving surface (WFDG Girders only), or roughened in preparation to receive an HMA overlay or cast in place deck.

While these girders have many uses and advantages they can get heavy quickly which needs to be taken into consideration when designing.

Benefits of WFDG and WFTDG girders:

  • Longer spans than comparative Deck Bulb Tee girders
  • May be able to reduce the number of girders compared to traditional Deck Bulb Tee girders
  • Reduced Field work
  • Same selection of girder depths as the traditional WF girders
  • Possible deck customization

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