I know this is a unique question. But if I were to basically drop 6 tubes of 1 1/4 geothermal tubing 275' deep into a former fresh air mine shaft before filling the 275' feet with dirt would the pipe be able to withstand the pressure of indirect hits as the dirt was dropped? Obviously the force reduces the closer to the top of the hole. But I'm trying to understand if I need to screen the dirt or just bite the bullet and pay up for drilled holes (2 times as much drilling costs)

I would think if you kept pressure on the lines and used a strong poly pipe it would work. I just don't know how to calculate it to give me more piece of mind.

Any help is appreciated.