USGS engineering help!?

Question

When using the Seismic Hazards Curves and Uniform Response Spetra program, how can you detimine SS and S1 in a siesmic zone D? I think I have it always wants to give me zone B and then two "site class" D's.

HELP!!!

Answer 1

You mean site class D?  I think the USGS site gives you S1 and Ss by lat / lon and then you have to modify it for site class by looking up Fv and that other variable who's name I forget.  In other words, I don't think the numbers you're getting from USGS have a site class in them.  You have to apply that.