>No. The roman bridges, the ones still up, lasted so long because they were ridiculously overbuilt. That seems like counterproductive for defense as destroying

>No. The roman bridges, the ones still up, lasted so long because they were ridiculously overbuilt. That seems like counterproductive for defense as destroying bridges were/is a common military strategy. Even the famous Trajan's Bridge (the longest arch bridge of that period) was supposedly destroyed to prevent barbarian invasions[1]. May be it was enough that the superstructure was purposefully weak to destroy it on demand and the substructure, foundation was overbuilt as you mentioned. [1] https://en.wikipedia.org/wiki/Trajan's_Bridge#Destruction_and_remains https://en.wikipedia.org/wiki/Trajan's_Bridge#Destruction_an...