Causes and analysis of steel structural failures - Assessment and Refurbishment of Steel Structures - page 54

Figure 2.35 Condition of mast No.71
after collapse

In replacing the wiring, a new route was determined on the basis of a detailed geological
research and new masts were located outside the slide area.

2.6 Results of defect analysis

It is obvious that the failure of steel load-bearing structures is rarely caused only by just
one thing. In most cases the failure is a result of many causes acting simultaneously. In
such cases the main cause is judged to be one whose influence on originating the failure
is determined as the greatest. Experience shows that the greatest number of collapses are
caused by erection errors, and errors in project design, as along with insufficient (or even
no) maintenance of the steel structures.
In the professional literature there are many analyses of failures and their causes. As
an illustration, examination of 150 analyses of failure gives the following proportions of
causes:
• Defects in erection 29.5%

• Errors in the project design and shop documentation 26.7%

• Operating failures (overloading, etc.) 14.3%

• Errors during fabrication 12.4%