Experimental study on static and dynamic mechanical properties of bolting wire mesh in rock burst roadway

In order to reveal the static and dynamic mechanical properties of metal mesh commonly used in rock burst roadway,and provide a design basis for the selection of metal mesh in rock burst roadway,the mechanical properties of longitude and latitude mesh,diamond mesh and reinforcing bar mesh are tested by using a special static and dynamic mechanical testing device,the stress characteristics and deformation of the metal mesh under static and dynamic loads are analyzed. The experimental results show that the maximum deflections of diamond mesh,longitude and latitude mesh and reinforcing bar mesh are 240,236 and 225 mm,respectively. The maximum load-carrying capacities of three kinds of metal mesh are 20,16. 2 and 77 kN. On the whole,the maximum deflection of three kinds of metal meshes is basically the same,but the load-bearing rate is different greatly,the load-bearing rate of the reinforcing bar mesh is the largest,followed by the longitude and latitude mesh and the diamond mesh. Under dynamic load,the maximum energy absorption capacities of diamond mesh,longitude and latitude mesh and reinforcing bar mesh are 1 743,938 and 2 010 J,and the maximum deflections are 350,420 and 360 mm,respectively. On the whole,the steel mesh has the largest energy absorption capacity and moderate deflection,followed by the diamond mesh,while the deflection is the smal- lest. Whether under static or dynamic load,the initial stiffness of diamond mesh is low and its bearing efficiency is slow. However,the diamond mesh has uniform force,can bear larger static and dynamic loads,and is not easy to break around the binder. The hook connection has good bearing and buffering capacity. The main drawbacks of the diamond mesh are that the bearing efficiency is slow and the supporting stiffness is too low,the main way to improve the sup- porting effect of diamond mesh is to increase the initial tension force. On the contrary,the stiffness of the longitude and latitude mesh is higher and the load-carrying efficiency is faster,but the strength is relatively lower,which is prone to the failure of the warp and latitude dislocation. When the longitude and latitude mesh is deformed, it is unevenly stressed,and the connection is easy to break,and the force of the wire is poor. In order to improve the supporting effect of longitude and latitude mesh, it is necessary to improve the binding strength between the longitude and latitude mesh. The reinforcing bar mesh has high initial stiffness,high strength and strong energy absorption capacity,but the weakness of the steel mesh is that the strength cannot be fully utilized,especially the low strength of the welded joints of the longitude and latitude mesh and the surrounding bindings,which restricts the support effect of the steel mesh. In order to improve its supporting effect,the strength of welding joint and binding should be increased.