![](https://hudsongeotechnics.com/wp-content/uploads/2024/08/GRA-1024x805.png)
Ground response analysis (GRA), also called site response analysis, is a critical tool for predicting how soil layers at a specific site will modify seismic waves during an earthquake.
Scroll down for a recent project example!
Hudson Geotechnics has high-level expertise in GRA. The California Geological Survey (CGS) reviewed a recent GRA report for a Site Class F site by HGI and stated the “…analysis is complete, comprehensive, and well documented in a report by Hudson Geotechnics… Hudson Geotechnics’ site response analyses is comprehensive…well designed and well executed.”
![](https://hudsongeotechnics.com/wp-content/uploads/2024/08/ProfilePlots.png)
2. Maximum profile response
![](https://hudsongeotechnics.com/wp-content/uploads/2024/08/TimeResponse.png)
1. Stress-strain response, strain, and excess pore pressure ratio time series colored by time
3. Amplification and attenuation of shaking
![](https://hudsongeotechnics.com/wp-content/uploads/2024/08/RecordRatios.png)