Wire was burnt and fused together underground at a Mobilehome park in California. They feed piggyback underground from unit to unit. The wire underground is direct burial cable but now we have to splice the wires, do we need a junction box installed for the splice underground or can they get spliced and buried as is?

Are you required to get a permit for this work? CA codes can be a real pain

CA codes can be a real painSo can their licensing rules.

This is a commercial job. Hire a qualified and licensed electrician.