Digging through perma frost

[Goldshark]

Howdy folks, I am putting in a portal, and the glacial debris/slide rock is frozen. I am told by some other guys digging 1500 ft. in elevation below me, the frost level is 30+ feet deep. Any of you guys/gals ever dig. through that stuff?

 

[Alan]

@Goldshark Are you going to try melting the face with a portable steam boiler or are you bringing in heavy pneumatic breakers to break through the portal entrance?

 

[Goldshark]

There are several options-1. drill and blast, 2. chip with pneumatic or hydraulic hammers, 3. either blow in warm air with a fan, or use a steam pipe. The steam pipe/hot water method would be more effective if I drilled a hole first. Just wondering what other methods I might be missing, and what other methods people have used. I do not want to thaw the back (roof ), as it is good for support until I get some timber in.

 

[DiamondRush_1]

Howdy folks, I am putting in a portal, and the glacial debris/slide rock is frozen. I am told by some other guys digging 1500 ft. in elevation below me, the frost level is 30+ feet deep. Any of you guys/gals ever dig. through that stuff?

That’s serious ground, I am curious what equipment you’ve found actually works best in that frost layer?