Conceptual Investigation of the Northridge’s Earthquake Structural Failures on Steel MRF by the Aid of Swiss Cheese Model

On January 17, 1994, the Northridge earthquake, USA, struck the southern California area, causing unexpected damage to beam-to-column welded steel moment-resting frames (WMRF). After 30 years of this benchmark earthquake, it is interesting to investigate this event from a different point of view, namely, through a combined consideration of forensic engineering and risk management. The Swiss Cheese Accident Model provides an excellent framework for understanding how a series of minor or major errors or failures can align to result in a catastrophic event. The study presents an effort to approach the failure of the Northridge earthquake of steel WMRF through the view of the Swiss Cheese accidental model. The investigation identified the layers of defense and their associated holes. Moreover, we discussed the weaknesses, corrective actions, and improvement actions.