Modification used:
- Used the site amplification equations from Campbell Bozorgina 2014.
- Calculated at both the user specified vs30 and the vs30 used in the calculation to get an amplification ratio
- Uses PGA at the station and estimates PGA1100 similar to HF
- This ratio is then applied directly to each intensity measure
- Improvements:
- Calculate PGA1100 from Mw / rrup
Analysis of Model
We used two sites: CCCC - vs30: 183 and SWNC - vs30: 377 to see the performance of the modification.
We calculated empiricals at these two sites for vs30 values of: 180, 200, 250, 300, 400, 500 and the original vs30.
The ratios below are calculated by shifting the original value to the specified vs30 and then comparing the logspace ratio.
The above two plots were cropped to the 25% error ratio.
From the above we have determined that a maximum 20% vs30 ratio would lead to a limit of 20% error ratio.
Future Work:
Assess vs30 std deviation to the 20% maximum vs30 ratio limitation
Extend PGA1100 estimation to be based on rrup / Mw