Inputs
Mr (MPa) ≈ MrF · CBR
Method — AASHTO 1993 / DPWH
- Mr = factor·CBR (MPa); Z_R from reliability.
- SN equation: log(W18) = ZR·So + 9.36·log(SN+1) − 0.20 + log[(ΔPSI/(4.2−1.5))/(0.40 + 1094/(SN+1)^5.19)] + 2.32·log(Mr/6.895) − 8.07.
- Iterate SN = 1..7 to match design ESAL.
Results
Z_R—
Mr—
Required SN—
Suggested layers (in)—