I've used www.seismicfactor.com. You input the address and the building parameters and it computes the corresponding site coefficients and base shears. I have double checked it in triplicate and it jives. It gets the lat and long based on the address in google maps.
David
Sent from my iPhoneOn 11/11/2011 3:51 PM, Tom.Hunt@fluor.com wrote:Whooa,
In California you should never use Zip Codes for looking up seismic values.
Heck, I don't even do that for any site, even if we're talking about Oklahoma or Kansas. Just makes no sense to go with a "zip code" when it's very easy to do exactly as you describe.