Back up and Shoring up

Back up verb - Move backwards from a certain position.

Shoring up and back up are semantically related In some cases you can replace term "Shoring up" with "Back up", this phrasal verbs are similar.

Shoring up noun - The act of propping up with shores.

Back up and shoring up are semantically related in strengthen topic. Sometimes you can use "Back up" instead a verb "Shoring up", if it concerns topics such as maintain.