Which mechanical effect most explains the eventual collapse of long, straight sections of Roman roads crossing unstable clay soils?

💡 Explanation

Differential heave causes roadbed cracking and eventual failure because upward soil movement is non-uniform; the effective stress is increased by the surcharge, therefore the consolidation settlement accelerates rather than remains stable, creating varying support along the road's surface.

• Which consequence appeared at Alesia when Caesar's circumvallation faced attack?
• Which moisture-delivery mechanism maintained productivity and averted desertification in the ancient terrace agriculture of the Andes?
• Which outcome results from water channel sedimentation in Mughal gardens?
• Which phenomenon allowed early furnaces using bellows to achieve sufficiently high smelting temperatures?
• Which maneuver resulted from lateen sails requiring shifted tacking angles?
• Which maintenance problem frequently occurred due to material properties of Inca rope suspension bridges?