No they aren't a glide bomb, they are a standard 500 lb fragmentation bomb fitted to the nose of a guided missile.
The bombs they use have been modified slightly for deeper penetration before blowing up. That means they have a time delay fuse fitted to the nose. It will delay the explosion for a few milliseconds to give it longer to travel through a solid object. Getting explosions to be under things is the most effective way to destroy them.
They are for blowing up bridges and bunkers, that's what they are for.
They would penetrate the deck of the bridge and blow up slightly after it passed through the deck such that the explosion would be under the bridge deck when it explodes That will loft that bridge deck up and off of the supports quite nicely. Hit about 5 adjoining sections and that will shut down the Kerch bridged for the duration of this war.