log base 10 of open paren cap W sub 18 close paren equals cap Z sub cap R center dot cap S sub o plus 9.36 center dot log base 10 of open paren cap S cap N plus 1 close paren minus 0.20 plus the fraction with numerator log base 10 of open paren the fraction with numerator cap delta cap P cap S cap I and denominator 4.2 minus 1.5 end-fraction close paren and denominator 0.40 plus the fraction with numerator 1094 and denominator open paren cap S cap N plus 1 close paren to the 5.19 power end-fraction end-fraction plus 2.32 center dot log base 10 of open paren cap M sub cap R close paren minus 8.07 1. Define Input Parameters Set up your spreadsheet with the following input cells: Federal Highway Administration (.gov) cap W sub 18
: A comprehensive tool available at CivilWeb Spreadsheets that includes unique design graphs to optimize layer thicknesses for specific loading conditions. aashto flexible pavement design excel spreadsheet
, which represents the total strength needed for the pavement layers: Traffic Loading ( cap W sub 18 log base 10 of open paren cap W
She started with 5 inches of HMA (5 * 0.44 = 2.2). Then 8 inches of crushed base (8 * 0.14 = 1.12). Running total: 3.32. Needed 0.88 more. Subbase? That would require 8 inches of gravel (8 * 0.11 = 0.88). Total SN = 4.32. Perfect. Then 8 inches of crushed base (8 * 0