Development of methods for calculating average loads on cylindrical shaft support
- 1 — Student, research assistant G.V. Plekhanov Saint Petersburg Mining University
- 2 — Student, research assistant G.V. Plekhanov Saint Petersburg Mining University
Abstract
Field observations show that the distribution of stresses around mine workings is uneven both in transverse and longitudinal directions. To take into account this distribution of stresses, we consider the interaction of the mine support with the surrounding rock massif. The roof support is considered as an elastic long closed cylindrical shell. The load acting on the shoring changes irregularly both along the shell and in the transverse direction: p = p(x,0), where x is the distance along the generatrix expressed in fractions of the radius; 9 is the central angle expressed in radians. Then, two cases can be considered: the support is under the action of axisymmetric radial load depending only on one variable x, the support is subjected to load depending only on the angle 9 The solution of the problem for the load of the form P = p(x, 9) is obtained by summing up these two solutions. Let's estimate average loads on a roof support for typical conditions of shaft construction in the elastic mode of interaction: R 0 = 3.0; R l = 3.5 m; R - 3.25 m; h - 0.5 m; Vj = 0.25; / = 0; v - 0.25; = 2 - 10 4 MPa; £ = 2 - 10 4 MPa Thus, when modeling vertical shaft support by a closed cylindrical shell the calculated average load is three times less than the corresponding value for a flat problem.