1. Engineering Perspective on Application of Simulated Ground Motions Jonathan P. Stewart & Emel Seyhan University of California, Los Angeles Robert W. Graves USGS Pasadena

2. Outline Need for verification, validation, and calibration (VVC) Validation procedures Validation of ShakeOut motions Calibration of high frequency IMs from Graves-Pitarka hybrid procedure

3. Need for VVC Verification: consistency of motions across computational platforms for common conditions Bielak et al., 2010 ShakeOut: example vel.(t)

4. Need for VVC Verification Validation: results of analysis generally consistent with recordings

5. Need for VVC Verification Validation Calibration: adjustment of parameters to achieve desired attribute of simulated motions

6. Validation Procedures Waveform comparison using earthquake data Graves and Pitarka, 2010

7. Validation Procedures Waveform comparison using earthquake data IM comparison to earthquake data Closest Distance (km) Graves and Pitarka, 2010

8. Validation Procedures Waveform comparison using earthquake data IM comparison to earthquake data IM comparison to GMPEs Frankel, 2009

9. ShakeOut Validation Motions from hybrid procedure

10. ShakeOut Validation Motions from hybrid procedure Analysis of residuals – 4 NGA GMPEs – R, V s30, Z for site i

11. ShakeOut Validation Motions from hybrid procedure Analysis of residuals Too-fast distance attenuation SO PH R R Star et al., 20xx

12. ShakeOut Validation Motions from hybrid procedure Analysis of residuals Too-fast distance attenuation Too-low intra-event standard deviation Star et al., 20xx

13. Calibration Adjustment to high frequency component of hybrid procedure

14. Calibration Adjustment to high frequency component of hybrid procedure Increase Q to slow distance attenuation Seyhan et al., 20xx

15. Calibration Adjustment to high frequency component of hybrid procedure Increase Q to slow distance attenuation Seyhan et al., 20xx

16. Calibration Adjustment to high frequency component of hybrid procedure Increase Q to slow distance attenuation Randomize Fourier amplitude spectra Seyhan et al., 20xx  A = f(M)

17. Calibration Adjustment to high frequency component of hybrid procedure Increase Q to slow distance attenuation Randomize Fourier amplitude spectra Seyhan et al., 20xx

18. Conclusions Engineers want to use simulated motions Needed for conditions having sparse data Verification – Validation – Calibration – Each step documented – Avoid circularity in use of data