Substructure design for bridges & structures

Bridge elements supporting the superstructure are substructure elements.

Design guidance including design considerations, modeling for seismic loads, and design of substructure elements such as columns, abutments, footings, shafts, piling, and concrete-filled steel tubes

Design memorandum

Design memorandum are issued as interim updates to the Bridge Design Manual. Active design memorandums supersede the Bridge Design Manual contents and are currently enforced.

Related manual chapters

Chapter 7 - Substructure Design (PDF 2.4MB) provides guidance for substructure design including:

  • Foundation modeling for seismic loads
  • Columns
  • Abutments
  • Wing and curtain walls
  • Footings
  • Shafts
  • Piling
  • Concrete filled steel tubes

Chapter 5 - Concrete Structures (PDF 18MB) is a secondary resource for substructure design providing guidance for cast-in-place reinforced concrete bridge elements.

Bridge Design Manual 

Complete Bridge design guidance is found in the Bridge Design Manual (M 23-50).

See all manuals and standards

Slow down – lives are on the line. 

In 2023, speeding continued to be a top reason for work zone crashes.

Even one life lost is too many.

Fatal work zone crashes doubled in 2023 - Washington had 10 fatal work zone crashes on state roads.

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95% of people hurt in work zones are drivers, their passengers or passing pedestrians, not just our road crews.