New Prequalified Seismic Moment Connection Supplement Available

Engineers now have more options for seismic design. AISC’s recently released Supplement No. 1 (ANSI/AISC 358s1-18) to the 2016 version of the AISC standard, Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic Applications (ANSI/AISC 358-16), allows designers to specify slotted web moment connections. In addition, the supplement includes a field bolted option for the popular SidePlate moment connection. The supplement has been fully integrated into the standard, and the complete document is now available for free download at

The supplement has been approved by the AISC Connection Prequalification Review Panel (CPRP) and is ANSI accredited. "The recently released supplement to ANSI/AISC 358-16 expands options available to designers for prequalified moment connections in special and intermediate moment frames for seismic applications," said Michael D. Engelhardt, chairman of the AISC CPRP. "Supplement No. 1 includes a new prequalified connection, known as the SlottedWeb moment connection. The supplement also significantly expands the existing prequalification for the SidePlate moment connection to include a field bolted option. With this supplement, there are now a total of 10 prequalified moment connections available to designers."

ANSI/AISC 358 is an essential companion to the AISC Seismic Provisions for Structural Steel Buildings (ANSI/AISC 341-16), as it outlines the requirements for the prequalification of specific seismic moment connections consistent with Chapter K of the Seismic Provisions.