IPIQ

E

FIXED CONSTRUCTIONS

E21

EARTH OR ROCK DRILLING; MINING

E21D

SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS

1/00

Sinking shafts

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E21D1/10

Preparation of the ground

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E21D1/12

by freezing

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E21D1/14

Freezing apparatus

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