Chapter 5: Other Designs
Anchor: #BABEGFCASection 1: Widenings
Anchor: #i1372103Design Recommendations
Design guidelines for various elements of new bridges may also be applied to bridge widenings. Complete a load rating and condition survey before plans are started. Ratings should be based on the 17th edition of the American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications for Highway Bridges, except that allowable stresses should be based on the minimum material strengths used on the original construction.
Refer to the Bridge Project Development Manual for additional requirements for load ratings and condition surveys.
Design widened portions for HL-93 loading using the AASHTO LRFD Bridge Design Specifications.
Show load rating and design loads on the bridge plan, for example, HS20(Existing) and HL-93(Widening).