I'm interested in developing a spreadsheet to estimate PVR; but it appears you would need to know the equations associated with the graphs............anyone?
Follow the procedure outlined in Tex-124-E, Figures 1 and 2 allow you to calculate PVR for each 1-ft layer for example, and you sum the results within your active zone. I made my own spreadsheet (took years to develop) because as you noticed the vertical strain vs pressure in Fig 2 is non-linear. If you work for a large firm i bet some coworker already has such a spreadsheet set up. Note also that the TxDOT PVR is only an index, it is not an estimate of maximum potential shrink-swell, particularly for CH soils (CL soils it is pretty good), so use with caution.
I've had no problem setting up a spreadsheet and digitizing the graphs. My problem is that I cannot seem to replicate
accurately enough the example calculations provided (i.e., I need to know the source of the graphs and/or the
equations, data points......something??
