|
Structures are commonly designed to withstand an earthquake of certain magnitude, say, the 50-yr earthquake,
i.e., that of magnitude recurring once every 50 years.
In 1967, I attended a one-week short course taught by the Late Prof. Alfonso Rico Rodriguez, a professional of
great stature and experience. Professor Rico
had headed a large government agency responsible for a large number of highway bridges in Mexico.
Professor Rico told his listeners
that his agency had experienced a 100-yr earthquake during his tenure,
and three bridges, out of more than 1000 total, had sustained
structural damage. After the earthquake, he gathered his staff for a fact-finding meeting.
The staff was prepared to answer questions
about the failed bridges. Instead,
Prof. Rico reminded his staff that since the earthquake was a 100-yr earthquake, and the design
was for a 50-yr earthquake, theoretically, ALL the bridges should have failed. Thus, he wanted to find out
why only three bridges had failed.
| ||
|
|
