Design Memorandum



TO:                  All Design Section Staff

FROM:            Jugesh Kapur
DATE:             March 1, 2005
SUBJECT:       Prestressed Girder Dimensions

This design memorandum summarizes the latest agreement between WSDOT’s Bridge and Structures Office and the Pacific North West (PNW) prestressed girder fabricators on the cross sectional dimensions of newly developed wide flange girders. The top and bottom flange dimensions remain unchanged but the depth of the girders will be slightly modified to match the current WSDOT prestressed girder designation. The attached details show the revised cross sectional dimensions for wide flange prestressed girders. The depths for WSDOT prestressed girders are summarized in the following table:

W42G & WF42G

3’-6”

W50G & WF50G

4’-2”

W58G & WF58G

4’-10”

WF74G & WF74PTG

6’-2”

W83G & W83PTG

6’-10 5/8”

W95G & W95PTFG

7’-10 1/2”

The PGsuper program and WSDOT standard drawings are being modified to reflect the revised cross sectional dimensions for standard prestressed girders. The revised girder dimensions apply to all new designs and projects currently under design. The revised girder dimensions do not apply to projects currently under contract.

Background:

The original development of WSDOT wide flange prestressed girders was based on hard metric dimensions. The soft conversion of SI units to US Customary units results in fractional dimensions often hard for design, detailing, and elevation calculations. The revised girder depths are consistent with old girder designations for simplicity.

If you have any questions regarding these issues, please contact Bijan Khaleghi at 705-7181.

Jugesh Kapur, P.E., S.E.

WSDOT- Bridge Design Engineer
360-705-7209