E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
E21D23/00—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor
E21D23/0052—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor with advancing shifting devices connected therewith
Landscapes
Engineering & Computer Science
(AREA)
Mining & Mineral Resources
(AREA)
Life Sciences & Earth Sciences
(AREA)
General Life Sciences & Earth Sciences
(AREA)
Geochemistry & Mineralogy
(AREA)
Geology
(AREA)
Pit Excavations, Shoring, Fill Or Stabilisation Of Slopes
(AREA)
Procede pour l'utilisation d'une plate-forme de forage en mer dans des conditions de presence de glace, et plate-forme equipee avec des moyens pour l'application de ce procede