|TO:||All Design Section Staff|
|DATE:||February 5, 1996|
|SUBJECT:||LFD Fatigue Criteria|
Per my memo of March 2, 1994, the HS-25 Truck load should be considered as the "design truck" for all new WSDOT bridges. For steel bridges, the fatigue analysis should be completed using the HS-25 loading, not HS-20.
For all WSDOT steel girder bridges, assume Case I road type when determining the number of stress cycles for design (AASHTO Table 10.3.2A).
Save this memo in BDM Chapter 7 until AASHTO LRFD takes effect.
cc: M. M. Lwin, Bridge - 7340