The first option would be to install a strut or struts.
How to fix broken cracked garage door.
A strut attaches to the inside of the garage door running the full length of the door.
Cut fiberglass sheets to fit over.
Super easy do it yourself.
Dry the area completely.
Then scuff the cup portion of the hinge with sandpaper where it will contact the adhesive.
There are a couple of things you need to do before you can remove the broken hinge.
Lock the garage door in an open position to prevent it from falling down and injuring you.
Start by removing the hinge from the door and preparing the damaged area photo 1.
The same goes for any concrete alternatives including wood or rammed earth.
If your garage door hinges are broken the best thing is to replace them.
A shopvac will do a good enough job of removing dirt debris stones and whatever else may be in there.
There are however still options available to you to repair the door and keep it working as it should.
With some simple angle iro.
The first option would be to install metal struts.
In this video we have a wayne dalton garage door with top panel damage.
Things you will need clean off the damaged area with soap and water and a rag or sponge.
The replacement of a strut will not fix a crack but it will allow for reinforcement to prevent further cracking thus allowing the door to function safely.
Apply petroleum jelly to the movable portions of the hinge to protect them from the glue.
While you may be able to rig up something to fix them the safest bet is to install new ones.
Sand away all burrs or raised edges on the crack in the fiberglass with sand paper.
Remove all dirt and grease.
These are usually made of metal and attach to the inside of the garage door running the full length of the door.