In IDA, I can plot acceleration vs inter-drift ratio of a building under some ground motions. In a attached paper by Dr. Kircil, authors plotted fragility curves though a standard normal variable (s), but I dont know how calculate s and plot Fig. 10. Please consider my problem.
Fragility curves are nothing more (or less) than plots of the cumulative conditional probability if failure with respect to some input parameter (Pf|a) We usually assume log-normal distribution of the Pf|a which is good enough approximation in many cases.
How to construct fragilities you may find in the attached report by EPRI, which is standard for the nuclear industry for more than 20 years now.
Thank you sir Stoyan Andreev for support,
Actually, In dynamic method, some ground motions are input, after that relation of Sa (or PGA) vs maximum drift ratio for each ground motion is plot. Next, in Kircil paper, the authors plotted Ln(Sa) vs a standard normal variable (s) from Sa-drift ratio. So, I dont know how determine the standard normal variable. If you know, can you explain more about it?
If you want to determine standard deviation, you can use sample standard deviation in excel spread sheet or use fundamental concepts about calculating standard deviation in excel. Then, you can follow the same steps and use lognormal distribution and calculate the lognormal standard deviation. If you have still need more information please refer above mentioned two papers and the link below:
http://web.stanford.edu/~bakerjw/Publications/Baker_(2014)_fragility_fitting_EQS_final.pdf
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