Peak Ground Acceleration for Liquefaction Potential

[Arcangelo]

HI:

I am doing a preliminary liquefaction potential analysis. I am using the methods outlined in SP117 (from the California...). Since I the project is located in an area with a low seismicity (upstate NY), and since I believe the data available to calculate the peak ground accelation (PGA)using predictive relationships are not reliable, I am trying to use the PGA values obtained at the USGS web site by zip code (i.e. I can obtain a PGA value with a PE of execeedence of 10% in 50 years). However, this value refers to Site Class B (rock site). Does somebody knows how I can relate this value to a class different than B (i.e. E)? Also, according to the IBC 2000 code, for a class site F, a specific site evaluation should be done. I belive the code is very vague. Does somebody refer to where I can find more info about this specific site evaluation. I have read Earthquake Engineering, by Dr. Kramer from the U of W., and I believe I know what to do. However, I would like more input. Thank

 

[pnmkapoor]

Arcangelo,
Few years back I did liqefaction analysis of potential liquefiable fine sandy soil. That time I used a technical paper by Seed & Idris. I don't remember the title. The paper had some graphs using the gradation properties of soil along with the ratio of shear strength of soil and ground acceleration for different earth quake zones.I can't recall anything more. You can search for that paper and hope it may be useful. Regards, Pnmkapoor