The interface mechanical properties and breakage analysis of the flexible isolation layer under ore drawing from a single funnel

摘要

The interface mechanical properties and the breakage analysis of the flexible isolation layer under the condition of single funnel ore drawing is an important research topic for the theory of loose medium flow under the flexible isolation layer. To grasp the distribution characteristics and variation rules of the force system from the microscopic level and to provide a theoretical basis for the strength design of the flexible isolation layer in the new mining method, the tensile stress and the compressive stress of the isolation layer are measured using a physical experiment, and the interface mechanical properties and rupture conditions of the isolation layer are analysed. The results showed the following conclusions: (1) Horizontally, with the increase in the distance between the measuring points and the centre point in the isolation layer, the tensile stress value of the isolation layer first increased and then decreased, while the compressive stress only decreased; the friction showed a trend of decreasing first, increasing later and decreasing again. (2) Longitudinally, the tensile stress value and the compressive stress value of the isolation layer increased with an increase in the descending height, while the friction first increased and then decreased with an increase in the descending height. (3) The isolation layer in the cavity is affected by the supporting force, and the variation in the supporting force received by the isolation layer in the noncavity region is the same as the compressive stress. (4) The isolation layer is most easily broken when h = 110 cm and s = 29.863 cm.