Thanks OverRun
That makes it clear, however I am still not quite clear about the load on one gear i.e. 47.4% given in the table I posted. I dont understand this:
if you have a weaker subgrade (more so as you move weaker and down to Very low CBR = 3%), the runway pavement gets pretty thick and you find that the loading from some of the other wheels in the gear start to load the pavement under your wheel, so their loads have to get added to this wheel load. You end up with an “equivalent single wheel load” which adds all these contributions together, and which is why for weak subgrades, the ACN is now pretty much double what it was for strong subgrades...
For interpolation from the tables I use excel and probably going to write a code in java script to make an app for my cell phone
Regards