Task 8: Site Response

The current state of the practice in seismic hazard analysis for loss estimation and structural evaluation is to: (a) perform a probabilistic hazard analysis using the NGA West models for NEHRP B/C boundary site conditions corresponding to VS30 =760 m/sec, and (b) apply the NEHRP site coefficients to adjust the estimated NGA ground motions to the desired NEHRP site class. The issue with this process is that: (a) the NEHRP site coefficients were developed over a decade ago, long before the development of the NGA West models; and (b) the NEHRP site coefficients are inconsistent with some of those predicted by the site terms included in the NGA West models. This task will examine the discrepancy between the NEHRP site coefficients and the site factors predicted by the NGA West models and attempt to resolve any discrepancy by either recommending modifications to the NEHRP site coefficients or modifying the NGA site terms, or both, as required.

Meeting documents

Reference manuscripts

  • To be posted soon.

Administrative documents