SPIRAL ANCHOR Russian patent published in 1999 - IPC

FIELD: mining industry. SUBSTANCE: spiral anchor can be used for strengthening of rock matter in underground workings, for fortification of slopes, foundations, etc. in construction industry. Anchor has stem with one or several protrusions arranged over spiral line along longitudinal axis of stem. Angle of incline α of spiral line is equal to 17-25 deg. Height of radial protrusions h is determined according to porosity P of rock matter being strengthened. Diameter of stem D and angle of incline of spiral line to longitudinal axis α together with other parameters are determined according to following relation: h = (0,12-0,14)p^0,48Dcosα. Aforesaid embodiment of spiral anchor ensures higher load-bearing capacity of stem with retention of high yieldability. EFFECT: higher efficiency. 3 cl, 6 dwg