基于弹塑性理论的节理处锚杆剪切变形机理分析

摘要

为了研究节理面处锚杆的剪切变形机制，建立了节理岩体中锚杆的受力模型，对锚杆在节理面处的剪切变形进行了理论分析，利用单位载荷法推导了节理面处锚杆竖向位移与载荷、节理宽度、材料性质间的关系。理论分析表明，节理岩体中锚杆的剪切变形过程为：小挠度变形阶段、弹塑性剪切变形阶段、塑性铰阶段；剪切变形至塑性铰阶段时，节理面处杆体将出现两个塑性铰；节理面处锚杆具有一段结构对称、载荷反对称部分；节理宽度对节理处杆体的弹性区、弹塑性区的分界面位置存在线性影响。%The stressing model of anchor bolt in jointed rock mass is established to study the shear deformation mechanism of jointed rock bolts,and the shear deformation at the joints is analyzed theoretically. Relationships between vertical displacement and load,and joint width and material properties of anchor bolt in the vicinity of the joint plane are deducted.The theoretical analysis shows that the shear deformation process of anchor bolt in jointed rock has the following stages,i.e.small deflection deformation stage,elastic -plastic shear deformation stage,and plastic hinge stage.In plastic hinge stage,two plastic hinges will appear on the anchor bolt near the joint plane.The anchor bolt has a section of body of symmetrical structure and anti -symmetrical load near the joint plane.The joint width has linear effect on Interface position between elastic region and elastic-plastic region near the joint.