Which structural effect enabled Roman concrete domes like the Pantheon to span vast distances?

💡 Explanation

When a dome structure expands outwards under its own weight, tension rings counteract hoop stress because they apply a compressive force inwards, maintaining structural integrity. Therefore tension rings resulted, rather than buttresses or flying arches (Gothic architecture), or post-tensioning (modern), which weren't used.

• Which risk increased during Roman road construction due to timber bridging soft terrain during wet seasons?
• Which risk increases when the foundation of a Roman castrum's defensive tower experiences differential settlement?
• Which risk increased the most in ancient Mesopotamian ziggurats that employed bronze reinforcing structural elements?
• Which process critically limited widespread adoption of iron tools in ancient Mesopotamia, despite iron ore abundance?
• Which structural consequence arises when oak timbers in 18th-century ship construction were not sufficiently seasoned before use?
• Which mechanism primarily enabled ancient rammed earth structures to withstand seismic activity?