So why all the earth works in front of the aeroplane?
Speculation on my part, but probably just restoring the area to its original state. It's a bit far over the horizon from here to be totally confident, but my theory would be that they removed the top soil from the tracks the aircraft was going to be taking on it's journey back to the hard to reduce as much as possible the obstruction it would present to the rolling of the wheels. The subsoil could be quite firm by comparison and present a suitably firm base for the tow out. I'm just basing this on occasional first hand experience in rescuing non aviation vehicles from somewhat similar situations.