锚杆支护网片动载力学性能试验研究

Experimental study on dynamic mechanical properties of mining anchor mesh

为了合理选择冲击地压巷道锚杆支护所需的网片,通过实验室试验从网片变形、承载力、位移及吸能等四个维度对比研究机编焊接钢筋网片和钢塑复合聚酯网片的动载力学性能,得到了两种网片在冲击载荷作用下的变形破坏方式及吸能特性。研究结果表明:冲击载荷作用下,机编焊接钢筋网片和钢塑复合聚酯网片破坏变形集中区域不同,机编焊接钢筋网片以“十字”形式向中心变形,破坏主要集中在钢筋网与固定压板接触处,钢塑复合聚酯网片破坏主要集中在受冲击载荷中心部位及聚酯网与固定压板接触处;网片冲击力时程曲线可分为缓慢承载阶段、波动稳定承载阶段及衰减阶段,随着冲击载荷的增加,机编焊接钢筋网片冲击力峰值明显大于钢塑复合聚酯网片,机编焊接钢筋网片对冲击地压巷道的支护能力更强;网片位移变形随着冲击能量的增加逐渐增加,机编焊接钢筋网片可抵抗冲击能量大于5000 J,钢塑复合聚酯网片可抵抗冲击能量为2000 J。

To reasonably select mesh for rock bolt support in rock burst roadways,a comparative study was conducted on the dynamic mechanical properties of commonly used machine welded steel mesh and steel plastic composite polyester mesh in coal mines,including deformation,bearing capacity,displacement,and energy absorption,using laboratory testing methods and a drop hammer impact testing machine.The deformation,failure mode,and energy absorption characteristics of the mesh under impact load were obtained.The research results indicate that under impact load,the failure and deformation concentration areas of machine welded steel mesh and steel plastic composite polyester mesh are different.The machine welded steel mesh deforms in a cross-shape towards the center,and the failure mainly concentrates at the contact between the steel mesh and the fixed pressure plate.The failure of steel plastic composite polyester mesh mainly concentrates at the center of the impact load and the contact between the polyester mesh and the fixed pressure plate;The time history curve of the impact force of the mesh can be divided into slow bearing stage,fluctuating stable bearing stage,and attenuation stage.As the impact load increases,the peak impact force of the machine welded steel mesh is significantly greater than that of the steel plastic composite polyester mesh.The machine welded steel mesh has stronger support ability for the rock burst roadway;The displacement and deformation of the mesh gradually increase with the increase of impact energy.Machine welded steel mesh can resist impact energy greater than 5000 J,and steel plastic composite polyester mesh can resist impact energy of 2000 J.The test results can provide a reference for the selection of anchor mesh in different support areas of the rock burst roadway.