Page 374 - Forensic Structural Engineering Handbook

STEEL STRUCTURES 11.5

• Document all sectioning and evidence removal
• Obtain exemplar components, if available
• Examination and documentation of evidence
• Initial, global visual examination
• Hands-off
• Do NOT move components (except for life safety)
• Documentation
• Photographs/video
• Detailed measurements, surveys, etc.
• Conduct witness and operational personnel interviews
• Obtain design and operating records
• Conduct detailed visual examination
• Failure analysis—failure mode identification
• Driving force assessment (e.g., stress and fracture mechanics analyses)
• Failure scenario construction
• Construct most probable failure scenarios
• Chronological listing of events
• Rule-out events not possible
• What was unique about the event
• Why did it occur in this system
• Root cause identification
• What is the most fundamental cause of the failure
• Will correction of this cause prevent further failures
• What were the contributing deficiencies
• Design
• Maintenance
• Operational
• Were there human performance issues associated with the root cause
• Other potential problems
• Can the failure occur in other systems
• Did the failure unknowingly affect other systems
• Corrective action plan
• Should mitigate or remove root cause
• Must be cost-effective
• Plan should be based on known methodologies
• Does not adversely affect other systems
• Reliable and implementable
• Performance monitoring
• Verify corrective action plan has been implemented
• Is plan effective
Detailed description of each of these tasks is beyond the scope of this chapter, but par-
ticulars of several of the tasks that are most relevant to steel structures—“failure mode iden-
tification,” “driving force assessment (methods of analysis),” and “fracture mechanics
analysis”—are discussed. Further information on root cause analysis can be found in Refs. 1
through 3.