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ICC-ES AC129 – Acceptance Criteria for Steel Moment Frame Connection Systems


ICC-ES AC129 outlines the acceptance criteria for steel moment frame connection systems used in the construction of buildings and other structures. These connections are critical components in seismic design, as they provide resistance to lateral forces caused by earthquakes.

The scope of AC129 includes:

  • Materials: specifies the types and grades of steel that can be used for moment frame connections.
  • Design and fabrication: outlines requirements for the design, welding, bolting, and inspection of moment frame connections.
  • Performance requirements: sets standards for the strength, ductility, and energy dissipation capacity of moment frame connections under seismic loading.
  • Testing procedures: describes the methods for evaluating the performance of moment frame connections through laboratory testing and analysis.

By adhering to AC129, engineers and fabricators can ensure that their steel moment frame connection systems are safe, reliable, and compliant with building codes. This helps to protect buildings and occupants from the damaging effects of earthquakes.

ICC-ES AC129 Accredited Inspection Agency

Applied Testing & Geosciences, LLC is accredited for performing inspections using the ICC-ES AC129 acceptance criteria.

Contact us for more information.



steel; moment frame; connection; seismic; ductility; plastic hinge; beam; column; weld; bolt; fracture; fatigue