Which risk increases when a Roman aqueduct's arcade bridge is constructed with significantly undersized voussoirs at the crown?

💡 Explanation

When voussoirs are undersized, shear failure occurs because keystone strength is insufficient to withstand thrust, causing keystones to slip and the arch to collapse. Sheer keystone slip results, rather than spalling, salt blooms or arch buckling, which require hydrostatic pressure, moisture transport or thermal stresses.

• Which outcome occurred when repeated cycles of draining and reflooding degraded soil salinity in ancient Mesopotamian agriculture?
• Which characteristic limits the size of early Mesopotamian bronze mirrors compared to later glass mirrors?
• Which mechanism primarily enabled the construction of the dome of the Florence Cathedral without extensive scaffolding?
• Which structural consequence frequently occurred as medieval stone fortifications aged and mortar weathered?
• Which effect resulted from slash-and-burn agriculture failing in deforested Mayan lowlands around 800 AD?
• Which angular relationship is corrected for when using an astrolabe to determine the time of day?