Abstract:
Reasonable roadway surface protection components can effectively control the deformation of roadway surrounding rock, and their control effect depends to a certain extent on the mechanical properties of the roadway surface protection components. To grasp the mechanical properties of surface protection components for coal mine roadways, a study on the mechanical performance tests of the combination of surface protection metal mesh and steel strip under static load conditions was carried out using a mining metal mesh mechanical testing machine. Six types of roadway surface protection components, composed of three types of metal meshes (steel bar welded mesh, hot-dip galvanized lapped mesh, and metal diamond woven mesh) combined with two types of steel strips (T-type and W-type) respectively, were installed on the mining metal mesh mechanical testing machine. The electric hydraulic jack of the testing machine continuously loaded the roadway surface protection components until the load suddenly decreased; the load-displacement curves of the roadway surface protection components were obtained using the cylinder displacement and load collected by displacement and load sensors, and the deformation and failure of the roadway surface protection components were recorded by a camera. Furthermore, the bearing characteristics of the metal mesh and steel strip combination system and the influence laws of related parameters on its bearing strength and deformation were analyzed. The results show that: ①under static loading conditions, with the constraint of T-type and W-type steel strips, the deformation and failure process of the metal mesh can be divided into the elastic deformation stage, plastic deformation stage, and progressive failure stage, among them, the bearing performance of the steel bar welded mesh fluctuates sharply when it is combined with the constraint of T-type and W-type steel strips; ②among the six combinations of roadway surface protection components, the combination of W-type steel strip + metal diamond woven mesh has the maximum bearing capacity (109.1 kN), and the combination of T-type steel strip + hot-dip galvanized lapped mesh has the minimum bearing capacity (63.2 kN); ③when combined with W-type steel strip constraint, the steel bar welded mesh has the maximum stiffness (0.2 kN/mm), the stiffness of metal diamond woven mesh is 0.16 kN/mm, and the hot-dip galvanized lapped mesh has the minimum stiffness (0.14 kN/mm). When combined with T-type steel strip, the stiffness increases of the metal diamond woven mesh, steel bar welded mesh, and hot-dip galvanized lapped mesh are 37.5%, 20%, and 7.14% respectively, which is conducive to inhibiting the formation of "mesh pockets".