It is just not very practical to perform DCP to a relatively deep depth. No matter for sandy or clayey type of material, it is not appropriate to use DCP blow count to estimate the footing settlement(especially for large footings). Locally, CPT and DMT have been widely used to calculate the...
Are you talking about IBC here?
I believe the seismologist can develop these curves for other probabilities of exceedance based on the same seimic source and attenuation relationship.
But why do you want to have the design spectrum for a PE of 9% in 500 years anyway?
