While digging a hole to plant a bush, I hit the cable supplying power to our lamp post. Due to erosion over the past 40 years, the cable was barely covered with earth, and is now partially exposed in places. The cable is UF rated, but is not buried deeply enough, not protected by conduit or GFCI, and exits the house underground. Also, I nicked the UF cable sheathing while digging. I've disconnected the hot from the switch until I can fix this.
To protect the cable where it exits the house, and to prevent water entry into the house, I've thought of using a PVC Type LB fitting, however it seems these can't be buried. Could I protect the circuit with a GFCI switch, seal the hole with silicone caulk, and just add dirt against the foundation to get to 12 inch depth where it can enter conduit?
The nicked sheathing could possibly be mitigated be running the whole length through conduit, or conduit plus a underground splice kit could be used.
The rest of the cable I'll bury in 3/4" or 1" PVC schedule 80 conduit buried 12 inches.
What is the proper way to fix this?