shoring vs propping up

shoring and propping up both are nouns.

Word	Noun	Adjective	Verb	Adverb
shoring	Yes	No	No	No
propping up	Yes	No	No	No

As nouns, shoring and propping up are synonyms defined as:

Other synonyms of shoring include shoring up.

shoring (noun)	propping up (noun)
the act of propping up with shores	the act of propping up with shores
a beam or timber that is propped against a structure to provide support