ELI5; how are bridges so secure in the ocean?

Question

I understand they pour concrete and use large bolts but how are they able to ensure the bridge remains stable? The ocean floor doesn’t seem too predictable so I’m curious how they confidently do this.

In: 1

Answer 1

There aren’t any bridges “in the ocean”, however the bedrock underwater is just as stable as it is on land, so they’re fine.