Causes and Investigative Methods
Accidents are called thus because they are unpredictable, and usually the result of some unexpected combination of unusual circumstances, with generally one or more humans involved in its causation and/or in suffering its consequences.
Accidents must be investigated because the victim (and/or his relatives and friends) and the society at large must know how the accident happened, to apportion responsibility, and to ensure that the triggers and circumstances of the accident be avoided or mitigated.
Most failures are quite straight forward, causing human, property, environment, or other harm or loss, and falling into one or more of a few categories of causes and requiring only a few well-known and simple investigative procedures, as in Table 1.
Table 1. Accident Causes and Investigative Methods
Cause |
Investigation |
a. General, for all causes |
Review of all existing documents and actions
Code conformity
Conformity with good practice
Accident re-creation, failure simulation
Destructive/non-destructive tests
Back analysis
|
b. Wrong or under design |
Design checks and back analysis |
c. Wrong erection or poor workmanship
|
Check procedures, supervision, etc.
Check connections
Check temporary supports
|
d. Overloading |
Recent and long-term history of use |
e. Wrong or bad materials |
Material testing (Including physical and chemical properties; high-tech, e.g. gas chromatography, mass spectrography)Strength testing |
f.Vagaries of weather, natural disasters; Acts of God |
Historical records versus design briefs and construction/fabrication records |