| 摘要 |
FIELD: mining; roof bolting used in mining industry for mine working support. SUBSTANCE: roof bolting includes load-carrying rod installed in hole with supporting head eccentrically mounted on its lock end, mineral filler, prop member with eccentric washer. Head has end part in form of truncated cone with angle of inclination to axis of load-carrying rod of 10-15 deg. Head has groove. Conical-to-cylindrical lengths ratio is 1:(1.8-2) and height of cylindrical part equals to hole diameter. Gap between cylindrical part and hole wall equals 3.0-3.3% of hole diameter. Mineral filler grains are have size 5-100% of gap. besides, in roof bolting, eccentric flexible washer is installed between mineral filler and washer. EFFECT: higher bearing capacity. |
