My first beehive got destroyed by a bear on the very first day. Now I'm planning my second. I know that everyone says that electric fences are the way to go, but it sounds like they are somewhat expensive and fiddly to get right. If you use low charge, the bear can walk right through it, thus the suggestions to bait the live wire, which seems cruel, and also likely to zap a few bears while others just go straight for the bees. If you use high charge, it's dangerous and you need electricity nearby, which means putting the hives near the house, which I didn't want to do.
I am thinking, instead, of wrapping the hive with ratchet straps and hoisting the thing up into a tree, and wrapping the trees with slippery metal sheeting and/or spikes. Or else suspending it away from the trunk, on a branch or cable that's too thin for the bear to access, kind of like storing food when camping.
I haven't done this, but you wouldn't be the first. seems like it would be pretty tricky to get right, but certainly doable if you're determined. the possibility of dropping a heavy hive full of bees and honey on myself when it came time to harvest or add boxes would probably keep me from taking this route. that risk could be engineered away, but with how much effort?
what about armoring the hives in some way? maybe a house for the hive made of stout lumber and anchored to the ground? I'm imagining something just bigger than your hive that it could slide in and out of for harvest or other work. you would obviously need to leave an opening for the hive entrance, too. if you're handy with metal, a frame made of angle could increase the bear resistance. concrete could work, too, but that's a lot of embodied energy. regardless of material, you would need a door on at least one side.
this would be the analog of a bear-proof box at a camp spot instead of hanging tasties from a tree.
which is pretty much your idea, and the guy claims it works.
If ratchet straps are strong enough to hold the thing together, then instead of strapping the hive to a concrete pad, I would think it would be just as robust to strap it to a stout tree. I'm just not sure I believe the straps really are that strong, or that the wood of the hive is. (I'm actually using hollowed out logs, which did survive the bear attack intact, so maybe as long as the bear couldn't knock it apart, that would work.
I'm not too worried about dropping the whole thing. I was thinking of strapping everything together, hoisting it into the tree, and strapping it to the tree, and leaving it attached with a strong rope or cable, which could then lower it back down. At any rate, I wouldn't be under it at the time.
I think if I were going to do that (and it makes sense to me to hoist a hive, that's where bees put them in nature) I'd go for a lightweight hive, not a full stacked Langstroth, due to the weight and the clunky form factor. Look up the top bar hives, the log hives and basket hives etc, something in there might be less problem to deal with.
your log hive is probably more suitable for hanging in a tree than modular hives. just make sure it's really secure. not just so it won't fall, but so it won't be knocking around when the wind picks up.
I don't know enough about bears to give any advice on keeping them out of the tree.