SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS

Introduced: September 1968

Last revised: January 1995

Classification Context

Section:: FIXED CONSTRUCTIONS
Class:: EARTH OR ROCK DRILLING; MINING
Subclass:: SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS

Description

Covers the construction, design, and engineering of vertical and horizontal underground excavations for mining, transportation, utilities, and storage purposes. Includes shafts (vertical access routes), tunnels (horizontal or inclined passages), galleries (larger horizontal chambers), and spacious underground voids for coal mines, metal mines, civil engineering projects, and subsurface infrastructure. Excludes general drilling and boring techniques classified under E21B, and addresses structural support systems, ventilation arrangements, and access provisions specific to these large-scale underground structures.

Additional Content

Pressure galleries, galleries specially adapted to house pressure water conduits Sewers

Related Keywords

subaqueous BUILDING(S)mining COALCOLLIERIES(2) DRILLING or sinking shaftsdesign of GALLERIES, constructing GALLERIESexcavating PIT(S)SAPPINGsubaqueous STRUCTURESSUBAQUEOUS structuresSUBWAY(S) tunnelsTUNNEL(S)TUNNEL(S) underwaterUNDERGROUND structuresUNDERWATER structuressinking WELL(S) shafts

14 direct subcodes

Child Classifications

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E21D 1/00 Sinking shafts
E21D 11/00 Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings , e.g. by assembling
E21D 13/00 Large underground chambers; Methods or apparatus for making them
E21D 15/00 Props; Chocks
E21D 17/00 Caps for supporting mine roofs
E21D 19/00 Provisional protective covers for working space
E21D 20/00 Setting anchoring-bolts
E21D 21/00 Anchoring-bolts for roof, floor, or shaft-lining protection
E21D 23/00 Mine roof supports for step-by-step movement, e.g. in combination with provisions for shifting of conveyors, mining machines or guides therefor
E21D 3/00 Raising shafts, i.e. working upwards from the bottom
E21D 5/00 Lining shafts; Linings therefor
E21D 7/00 Shaft equipment, e.g. timbering within the shaft
E21D 8/00 Shafts not provided for in groups
E21D 9/00 Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries

Top Applicants

Top 10 applicants by patent filingsfor class E21, 2013–2023, worldwide · Source: EPO PATSTAT

HALLIBURTON ENERGY SERVICES GROUP US 26,607
PETROCHINA COMPANY 14,382
SINOPEC (CHINA PETROCHEMICAL CORPORATION) 10,137
CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 6,517
BAKER HUGHES US 6,269
SCHLUMBERGER TECHNOLOGY US 5,929
SAUDI ARABIAN OIL COMPANY SA 5,880
SOUTHWEST PETROLEUM UNIVERSITY 4,477
CHINA UNIVERSITY OF MINING AND TECHNOLOGY 4,357
SCHLUMBERGER TECHNOLOGY NL 4,219