Analysis of Events in Recent Structural Failures

A study of nearly 150 recent major collapses and distresses of structures around the world discloses that external events and deficiencies in the areas of construction and design were the principal sources of failures. More than one‐third of the surveyed structures were bridges, and the remaining were low‐rise, multi‐story, plant‐industrial, and long‐span buildings. The major incidents in the category of external events were the lateral impact forces and other unexpected live loads on bridges, and explosion impact loads in concrete silos. Construction deficiencies included falsework and concreting faults in several concrete structures and inadequate welding operations in steel bridges. Design deficiency related events were found to vary with the type of the observed structures, but a significant number of failures were attributed to lack of knowledge in long‐term creep and shrinkage effects on prestressed concrete members. These findings suggest that attention should be directed to three areas: (1) Identification of potential deficiencies from past failure data; (2) enhancement in procedural methods during design and construction operations; and (3) incorporation of risk analyses of structures during their service life and construction phases.