On 8/24/2011 7:18 PM, Sean Donelan wrote:
On Wed, 24 Aug 2011, Leigh Porter wrote:
Indeed, we are not going to be building earthquake proof buildings in London for example.
Of course there is no such thing as earthquake proof. The Earth is still a single point of failure :-)
Essential facilty design usally takes the "standard" design probabilities for various hazards (heat, cold, wind, rain, earthquake, etc) and multiplies it by a larger safety factor. It doesn't mean designing for the most extreme situation possible anywhere. You've got to rely on the geologists and structual engineers to know their stuff.
In any case, its still just a probability. No matter how small the probability, any facility can still have a failure. Have a backup plan somewhere else with a different set of hazards.
Many years ago I was taught that "earthquake proof" means the building doesn't kill the occupants and not that the structure survives unscathed.. As examples, they used a hospital that was damaged in the magnitude 6.6 Sylmar quake of 1971 The building was basically destroyed but only four people were killed.