煤矿巷道锚杆支护过程中，锚杆剪切破坏现象时有发生，严重影响着巷道支护的稳定性，特别是巷道周边岩层节理发育区域，其锚杆剪切破断最为频繁。针对煤矿巷道锚杆剪切破断的问题，通过现场调研锚杆破坏情况、查阅相关资料的方式，确定了造成煤矿锚杆剪切破断的主要原因。根据理论分析，提出了在剪切节理面处进行扩孔锚固的方式来增大剪切节理面处锚固体截面直径，降低剪切节理面处锚固体所承受的最大剪应力，提高锚固系统的整体刚度，进而增大锚固系统的整体抗剪切性能。采用数值模拟的方法，对普通锚固、正楔形扩孔锚固和圆柱形扩孔锚固3种锚固类型进行受力分析，以锚杆剪切位移、锚杆剪切变形影响范围及锚杆受力为指标，确定了剪切节理面的最佳锚固方式为正楔形扩孔锚固;在正楔形扩孔锚固的基础上，通过改变不同的扩孔位置，分析锚杆的剪切位移和剪切载荷，确定了扩孔位置在50 mm处最佳。设计加工相应的锚杆剪切试验装置，并从剪切载荷和剪切塑性铰的轴向间距两个方面进一步验证了正楔形扩孔锚固可有效改善剪切节理面处锚固体的受力状态，降低锚杆所承受的剪切载荷，增大剪切塑性铰的轴向间距，减小锚杆的剪切变形，增强锚杆对围岩错动剪切的适应性，进而提升锚固系统的整体抗剪性能。

During the bolt support process in coal mine roadway,the shear failure phenomenon of anchor bolt has oc- curred frequently,which seriously affects the stability of roadway support,especially the development area of joint rock around the roadway,and the shear failure occurs most frequent. Aiming at the problem of shearing and breaking of bolts in coal mine roadway,the main reason for the shear failure of coal mine bolts was determined through the site in- vestigation of bolt damage and the literature review. According to the theoretical analysis,the method of reaming an- chorage body at the shear joint surface was proposed to increase the diameter of the anchor section at the shear joint plane and reduce the maximum shear stress of the bolt at the shear joint plane. The overall stiffness of the anchoring system was improved,thereby the overall shear resistance of the anchoring system was increased. Using the method of numerical simulation,and anchorage stress analysis,the stresses of three types of anchoring,general anchoring,positive wedge reaming anchoring and cylindrical reaming anchoring were investigated. Based on the shear displacement of the anchorage,the influence range of the shear deformation of the bolt and the stress of the bolt,the optimal anchoring mode of the shear joint was determined as the positive wedge reaming anchor. On the basis of the positive wedge-shaped reaming anchoring,the shear displacement and shear load of the bolt were analyzed by changing the different reaming positions,and the reaming position was determined to be optimal at 50 mm. The corresponding bolt shear test device was designed and processed,and it was further verified from the two aspects of shear load and axial spacing of shear plastic hinge that the positive wedge reaming anchor can effectively improve the stress state of the anchor at the shear joint surface. Moreover,the shear load of the bolt rod can be reduced,the axial spacing of the shear plastic hinge can be increased,the shear deformation of the bolt can be reduced,the adaptability of the bolt rod to the displacement of the surrounding rock can be enhanced,and the anchoring system can be improved for the overall shear resistance.