Consideration of Human Factors in Investigations of Structural Failures

Investigations of claimed structural failures often lead to conclusions based on structural factors including strength and serviceability. Typically, these conclusions are absolute since they result from objective comparisons of results to limits prescribed by owners and/or governing agencies. Occasionally, however, the failure of a structure may be defined by human factors, which are more subjective. A case is presented herein (Kellogg 1988) that describes the evolution of an investigation from one of only structural factors to one that included human factors. Discussion focuses on "failure" being defined by the inability of the structure to restrict human annoyance. In this case, excessive building vibrations were claimed to render the occupants unable to perform their work as intended. Investigation, presentation, and solution processes are described in order to contrast differences between absolute failure decisions based on structural factors and relative failure decisions based on human factors.