I'm comparing seismic deformation of an embankment using the Makdisi & Seed approach to more recent methods by Bray et al (1997 and 2007).  I am finding at least two different versions of charts for the Makdisi & Seed method.  The one in the Kramer text has the period (To) of the embankment on one of the chart axes.  The other version of the chart does not have To.

I have two questions for anyone familiar with these charts:

1) Do they both give the same answers?

2) One one of the charts where you need to compute Kmax as a function of the embankment and potential failure surface geometry, the horizontal axis has Kmax/PGA/g.  Would you divide your PGA by g (32.2 fps^2) to come up with Kmax, or is this just indicating a divison by g to make Kmax dimensionless.  I thought the latter, but have seen the the divison done in the Kramer text and it would obviously make a big difference.

Thanks