Specific Ground Motion Hazard Analysis in West Virginia

[moe333]

Hi All,

I'm trying to perform a Site Specific Ground Motion Hazard Analysis in West Virginia. I have done these previously in California where there are many discrete faults but that isn't the case in West Virginia.Is this analysis typically performed in this part of the country to attempt to reduce the seismic design category as is the case in California?

My problem is: what fault would I use for the deterministic part of the analysis? The discrete faults are 100's of km's away where attenuation relationships are not considered valid. The only one valid for the Eastern US I have access to is Toro (97). Is this a commonly used relationship in this part of the country? Most of the probabilistic seismicity based on the 2008 USGS deaggregation is from gridded sources.

Is it customary to use the gridded source with the R and M as shown in the 2008 USGS deaggregation as a discrete fault in the deterministic analysis? The other smaller problem is that I'm using the 2008 USGS Deaggregation for the probaibilistic part of the analysis. It will only provide values for Vs-30 of Site Class A and B/C, whereas I need it for Site Class C. I'm assuming I can just apply Fa and Fv coefficients to get to a Site Class C?Thanks, any suggestions are appreciated.

One approach I am considering is to use the Deterministic Lower Limit as the Deterministic MCE as specified in ASCE 7-05. However, this may be unconservative and I'm not sure how the reviewers would perceive it.

 

[MiketheEngineer]

You might try the local building department. They usually can be very helpful

 

[dgillette]

Hi moe333. Do you have access to the Bulletin of the Seismologic Society of America? May be obsolete or obsolescent or irrelevant, but by skimming reference lists, I found:

Boore, D.M. and G.M. Atkinson (1987), "Stochastic prediction of ground motion and spectral response parameters at hard-rock sites in eastern North America," BSSA #77, pp. 440-467.

Toro, G.R. and R.K. McGuire (1987), "An investigation into earthqauke ground motion characteristics in eastern North America, BSSA, #77, pp.468-489.

Nuttli, O.W. (1981), "Similarities and differences between western and eastern United States earthquakes, and their consequences for earthquake engineering," Proc. Conference on Earthquakes and Earthquake Engineering: The Eastern US, Knoxville TN, v.1., 24-51.

I'd hunt for other papers by Gail Atkinson also. I think she's at a university in eastern Canada, and may still be working on eastern North America attenuation and such. A paper by McGuire probably has too much higher math for me to be able to read in less than a month.

I have a feeling that the local building department almost anywhere in the east is going to say "Huh?" when you ask them about any sort of higher-level seismic study (except near Charleston SC).

Regards,
DRG

 

[msucog]

And moe, keep in mind that the distance to consider in the CEUS is much larger than WUS. In WUS, it might be 200km whereas CEUS is 700-1000km. Deterministic rarely "wins" unless you're on top of or very near the faults (New Madrid, Charleston, East TN, etc).

Toro is one of the predominant references here. There are some others and some fairly new sets of AEs. Toro also has newer AEs than '97.