Steel moment frames have historically had fairly good seismic performance from the life-safety standpoint. Following the 1994 Northridge Earthquake, steel moment frames were found to have suffered damage to the beam-column joints, resulting in significant modification of building code requirements. Typical damage to steel moment frame structures is as follows:
- Joint Failure (Cracks develop through the beam-column joint)
- Column Buckling (Strong beam/weak column conditions or soft story irregularities may result in column failure)
- Excessive Drift (High lateral deflection may result in significant non-structural damage.
