Abstract:
In order to study the reasons for the difference of point load test results caused by indenter angle, the stress distribution law in coal and rock mass under the action of point load with different indenter angle was studied by theoretical analysis and numerical simulation. The results show that compressive stress and tensile stress are generated in coal and rock mass under the action of different indenter angle. The vertical stress presents an "inverted double peak shape" and a "circular shape" in the vertical and horizontal sections, respectively. Near the loading point, the coal and rock mass is subjected to compressive stress in all directions, and decreases with the increase of the distance from the loading point. The horizontal tensile stress and vertical tensile stress in the direction of the vertical loading axis are subjected within a certain distance from the loading point, and the area of horizontal tensile stress is spherical. The stress state of coal and rock mass under the action of different indenter angle is studied. It is found that the indenter angle has little influence on the form of stress distribution, but the stress concentration of coal and rock mass is more intense under the action of small indenter angle, which further affects the stress value of coal and rock mass sample when it is damaged.