2% in 50 Years deducted from 10% in 50 Years
2% in 50 Years deducted from 10% in 50 Years
(OP)
Hi experts,
How can I calculate 2% in 50 years from the following map which is 10% in 50 years? Let's say just for Santiago. Thanks.
Max.
How can I calculate 2% in 50 years from the following map which is 10% in 50 years? Let's say just for Santiago. Thanks.
Max.





RE: 2% in 50 Years deducted from 10% in 50 Years
I'm not sure if you're actually looking for Santiago's ground acceleration, or if you just want to know how to convert accelerations due to varying probabilities. But, for what it's worth, the US Department of Defense has the following ground accelerations for Santiago for 2% exceedance in 50 yrs.:
Ss=1.65g (ground acc. for buildings w/period of 0.2s)
S1=0.75g (ground acc. for buildings w/period of 1.0s)
These values are probably very approximate and conservative, though.
Hope this helps you out a little.
RE: 2% in 50 Years deducted from 10% in 50 Years
Thanks a lot for the info.
Do you have a bit of explanation on Ss & Si quantities and how they are used?
Many more thanks,
Max.
RE: 2% in 50 Years deducted from 10% in 50 Years
The Ss and S1 values are spectral accelerations at building periods of 0.2s and 1.0s, respectively. This system is used in the NEHRP references, FEMA 368 and FEMA 369 (which you can order for free), and also in the IBC. You can look at these or another seismic design reference to get a better understanding.
Shemp
RE: 2% in 50 Years deducted from 10% in 50 Years
In new york, there is factor of 2 difference between 500yr and 2500yr, whilst in California it is 2/3. The answer is it depends.
Michael Ludvik
RE: 2% in 50 Years deducted from 10% in 50 Years
Is there any American building code which stipulates on a procedure for calculating PSHA for a locality?
Max.