To 3 or Not to 3? (PDH)
Presented by: Ron Hamburger, SE, PE and John Hooper, SE, PE
Designing seismic force-resisting systems per AISC 341 permits the use of large R values (5 to 8), reducing seismic design forces, required frame and foundation strength, and stiffness requirements. However, this comes at a cost. Members must be seismically-compact, driving up steel tonnage; extensive lateral bracing of beams and columns may be required; and, connection designs must meet rigorous criteria that drive up complexity and cost. Where permitted as an alternative, design for R=3, requires design for higher forces, but often results in a more economical solution through avoidance of these AISC 341 requirements. This presentation will examine this trade-off and how the selection of a SFRS affects the total building cost, not just the steel tonnage.
This course is based on a AISC live webinar (1/27/2026).
You must view the video and pass the quiz to receive a PDH certificate for this course.
If you do not need continuing education credit, you can view the content here for free.