TUBING FOR COAL DESCENT Russian patent published in 1996 - IPC

FIELD: mining. SUBSTANCE: support is made in the form of individual rings comprising metal tubings with caissons, and at least one tubing in the ring is made of strength material characterized with brittle fracture behavior. Parameters of caisson ribs of each metal tubing are found of the following expressions: ; σ_d, where "S" is caisson rib width, m; "B" is caisson height (caisson depth), m; "P" is tubing strength at radial load, N; is bearing strain of the rock being displaced, Pa; "L" is perimeter of ribs coming in contact with the rock, m: "Q" is forecasting support rock pressure, Pa; "R" is bearing capacity of the tubing, Pa; is rock shift at working boundary, m; "D" is well diameter, m; "m" is stratum thickness, m; u_r is possible converging of lateral rocks at support rock pressure, m. EFFECT: supporting raises at exploitation of thick strata of steep slope. 2 cl, 3 dwg