Which event most immediately renders a medieval motte-and-bailey vulnerable?

💡 Explanation

Extensive undermining causes structural collapse because it removes soil support, implementing stress intensification. Undermining concentrates and exceeds the soil's shear strength at critical locations; therefore, collapse follows rather than simply gradual settling, displacement via overload, or environmental damage alone.

• Which structural consequence results in medieval rope bridges when exceeding fiber's tensile strength?
• Which outcome arises when early wrought iron firearms used gunpowder with excessive granular impurities?
• Which risk increased when 18th-century naval ships exceeded design displacement during transatlantic voyages?
• Which function did epicycles serve within the Ptolemaic system of astronomy?
• During Roman sieges, which risk increased for wooden siege towers operating near city walls defended with heated liquids?
• Which vulnerability was most exploited for undermining castle wall structural integrity at sieges before the advent of gunpowder?