Aashto Flexible Pavement Design Excel Spreadsheet -
AASHTO Flexible Pavement Design: The Ultimate Guide to Excel Spreadsheets
The spreadsheet solves for SN required, then checks the layered system: aashto flexible pavement design excel spreadsheet
5. Validation
- Validate spreadsheet against two or three published AASHTO example problems (cite AASHTO Guide example numbers). Show tabulated comparison: input case, published SN/thickness vs spreadsheet result, percent difference.
- Discuss sources of discrepancy: rounding, assumed coefficients, use of R-value vs Mr, drainage coefficient, interpolation.
- Problem: The equation cannot be rearranged explicitly for $SN$.
- Solution: The spreadsheet utilizes Excel's "Enable iterative calculation" feature in Options > Formulas. The formula cell references itself to converge on a solution automatically.
): High-traffic highways typically require 90-95% reliability, while local roads might use 50-80%. Resilient Modulus ( MRcap M sub cap R AASHTO Flexible Pavement Design: The Ultimate Guide to
, which is then converted into layer thicknesses. Since the equation is implicit, developing an Excel spreadsheet requires using the tool to find cap S cap N iteratively. Journal of Soft Computing in Civil Engineering AASHTO 1993 Design Equation The required cap S cap N Validate spreadsheet against two or three published AASHTO
3.1 Input Section
| Parameter | Typical Range | Excel Cell Example |
| :--- | :--- | :--- |
| Reliability (R%) | 50% - 99.9% | B4 = 90 |
| Standard Deviation (So) | 0.35 - 0.50 | B5 = 0.45 |
| Initial PSI | 4.2 – 4.5 | B6 = 4.2 |
| Terminal PSI | 2.0 – 2.5 | B7 = 2.5 |
| ΔPSI | (Initial – Terminal) | B8 = B6 - B7 |
| Resilient Modulus MR (psi) | 3,000 – 30,000 | B9 = 5000 |
| 18-kip ESALs (W₁₈) | 10^4 – 10^7 | B10 = 2.5E6 |