Yeah, that's a tough one. My best (and only partial) guess would be:
ეწოდა იმ ღვაწლის აღ-
სანიშნავად რომელიც [...]
მდივანს გნ კოკაიას
1946-1948 [...] ფოთი-
The avenue in honor of Grigol Kokaia was named to mark those achievements which Poti's civil committee's secretary GN Kokaia [has accomplished?] [during?] 1946-1948 in the matter of the construction of Poti-Chaladidi's avenue[s?].
One of my dictionaries, Dunwoody, defines ხეივ[ა]ნი as "trellis covered in vines," but another, Apridonidze, says it means "avenue lined with trees," and a Google Images search suggests this is the more accurate meaning. On the actual inscription it looks more like სეივანი, but that isn't a word. Perhaps those vine-covered trees in the background are the avenue in question.
EDIT: I just realized the word at the beginning of the Russian part is аллея, so I think that confirms the ხეივანი thing.
Chaladidi is apparently a village in Samgrelo. The Russian at the very bottom must say Поти-Чаладиди, but I can't make much more of it out.
It looks to me like:
Glory to the heroes!
I agree, that's what it looks like.
I also want to correct this one. It literally says "... is [the] sun's darkening," and it occurs to me "darkening" in the context of the sun means "eclipse," so the better translation would be "a hero's death is an eclipse of the sun." I think I was being a little too creative.