its a sears garage door opener
If it has the IR eyes you can bypass them by re wiring them at the power control box. Or you could use the emergency release and open and close it manually. Sometimes you can also adjust the sensitivity on the back of the motor to control when it will open and close.
There should be an adjustment on the box hanging from your ceiling that adjusts where the door stops. Adjust it until the door stops just at where the concrete is now. You will need a ladder to reach it and of course your car will have to be outside out of the way. I think it takes a small screwdriver to adjust and it is marked as to what they are. Don't mess with the one that sets the pressure, just where it stops.
Richard has the idea,adjust downward force of opener,so it will stop at the raised concrete.Block off the rest where it is not touching,to keep undesirables out.
Depending on the type of opener you have you need to adjust the sensor that tells it that it is down or adjust the sensing circuit that tells it the door is down. Sometimes there is a magnetic switch on the chain rail or you must look in the owners manual for instructions on how to adjust it.
Pull the cord go to manual pull the door down an put rugs etc around opening take care of that in the summer.
