鉴于目前井下金属网常见的强度及刚度失效2类破坏方式严重制约巷道安全可靠性问题.采用自主研发的金属网静载试验系统对3类金属网进行了测试.得到了3类金属网在垂直载荷作用下的支护强度.刚度及变形破坏方式,借助有限元分析软件Ansys得到了3类金属网在垂直载荷作用下的应力分布规律,采用理论分析的方法得到了3类金属网的传力机制问题.并进一步根据3类金属网的力学响应特征.应力分布规律及传力机制分别给出了结构优化建议.研究结果表明:① 金属网支护系统在垂直载荷作用下的载荷-位移曲线变化可分为载荷传递阶段.网丝变形阶段及结构破坏阶段3部分.② 钢筋网具有高刚度支护特征.菱形网具有高强度支护特征.垂直载荷作用下经纬网的网丝错动会大幅度降低其支护强度及刚度.③ 钢筋网及经纬网以中心[十"字型区域内的网丝承受轴向应力.菱形网以中心[X"字型区域内的网丝承受轴向应力.④ 钢筋网支护系统在承载过程中呈现出中心[十"字型传力方式.菱形网呈现出中心[X"字型传力方式.经纬网网丝在外部载荷作用下由高应力区向低应力区滑移.⑤ 直接决定金属网支护作用的边界网丝.在垂直及水平方向上分别受到剪切及扭曲作用.且绑丝强度对边界网丝的水平扭曲作用影响较大.⑥ 3类金属网是否能进行有效支护.应围绕传力机制问题分别进行局部绑丝加固.节点约束防滑及配套锚杆间排距优化等加强措施.

In view of the common failure modes of strength and stiffness of underground metal mesh seriously restrict the safety and reliability of roadway,the self-developed metal mesh static load test system is used to test the three types of metal mesh,and the support strength,stiffness and deformation failure mode of three types of metal mesh under vertical load are obtained;the three types of metal mesh are obtained with the help of finite element analysis software According to the mechanical response characteristics,stress distribution law and force transmission mechanism of the three types of metal mesh,the structural optimization suggestions are given. The results show that:① The load displacement curve of metal mesh support system under vertical load can be divided into three parts:load transfer stage,mesh deformation stage and structure failure stage. ② The results show that the reinforcement mesh has the characteristics of high stiffness support,and the rhombic mesh has the characteristics of high strength support. The mesh dislocation of the warp and weft mesh under the vertical load is an important reason to reduce the support strength and stiffness. ③ The mesh wire in the central [cross" shaped area of the reinforcement mesh and the warp and weft mesh bears the axial stress in the central [X" shaped area. ④ During the loading process,the steel mesh support system presents the central [ten" type force transmission mode,the diamond mesh support system presents the center [X" type force transmission mode,and the warp and weft mesh wire slides from the high stress area to the low stress area under the external load. ⑤ The boundary wire,which directly determines the supporting effect of metal mesh,is subject to shear and torsion in vertical and horizontal directions respectively,and the strength of binding wire has great influence on the horizontal twisting effect of boundary wire. ⑥ Whether the three kinds of metal mesh can be effectively supported or not,we should focus on the problem of force transmission mechanism to carry out local wire binding reinforcement,node constrained anti-skid and optimization of row spacing between supporting bolts.

1 金属网分类及变形破坏特征

2 金属网力学性能试验

   2.1 金属网力学性能实验室测试

   2.2 试验结果及曲线分析

   2.3 支护强度及破坏分析

   2.4 支护刚度及变形分析

3 金属网应力分布数值模拟研究

   3.1 数值模型材料参数

   3.2 金属网抗变形能力分析

   3.3 [梁"单元应力分析

4 理论分析

   4.1 金属网传力机制分析

   4.2 金属网受载变形分析

   4.3 防止金属网支护失效的改进方法分析

5 讨论

6 结论