Which outcome resulted from countermining beneath a besieged castle wall?

💡 Explanation

Countermining creates instability causing collapse; undermining employs Soil arching. This induces a concentrated load leading to shear failure of the wall's base, because a void is created, therefore collapse occurs, rather than simple settling or minor displacement.

• Which limitation most affected Inca suspension bridge span length?
• Which outcome results when wooden siege towers approached walled cities?
• Which instability arises on a wooden sailing ship when cargo shifts rapidly during a sharp turn?
• Which outcome resulted because stepped construction facilitated water distribution throughout Mughal gardens?
• Which risk becomes pronounced when traditional Chinese cast-iron plowshares encounter hardpan soil?
• Which outcome frequently resulted when ancient Andean terrace farms cultivating maize experienced prolonged drought conditions?