This load combination is applied to earthquakes. The factor for live load (γEQ) shall be determined on a project-specific basis.

• A. Extreme Event I
• B. Extreme Event II
• C. Service I
• D. Fatigue and Fracture limit states

Answer: (B)

In earthquake design, there are extreme-event load combinations that combine seismic effects with other loads to capture rare, severe conditions. Among these, one combination specifically allows the live-load factor during an earthquake (gamma_EQ) to be determined on a project-by-project basis. This project-specific flexibility helps reflect how a building is actually used and occupied during an earthquake, avoiding unnecessary conservatism while still protecting safety.

That’s why the correct choice is the Extreme Event II combination. The other options serve different purposes: a service-state combination is for regular, non-seismic serviceability checks, and a fatigue/fracture limit-state combination addresses material failure over time. The first extreme-event option uses fixed factors and does not permit the project-specific gamma_EQ, which is why it’s not the correct choice in this context.