The Mud-Season Passability Bound for an Unsurfaced Clay-Loam Road: Bearing Strength, Drainage and Gravel

A daily moisture and bearing-strength model for a clay-loam road: a loaded pickup fails on 120 days untreated, 63 days with side drainage alone, 106 days with a 150 mm gravel cap alone, and 2 days with drainage plus a 150 mm cap. An expansive clay at saturated CBR 1.2 percent fails even under a 300 mm cap. SIMULATED, NOT MEASURED.