基于围岩变形的全长粘结型锚杆受力特征研究

Study on Mechanical Characteristics of Full-Length Bonded Bolt Based on Surrounding Rock Deformation

为研究围岩变形与锚杆相互作用关系,基于围岩变形推导出仅由围岩变形引起的巷道全长粘结型锚杆界面剪应力解析式,通过解析式分析锚杆界面剪应力影响因素,根据中性点理论,将锚杆分为两段,中性点前和中性点之后,将围岩变形以及引起围岩变形的内力以应变能的形式代入,求出锚杆中性点前剪应力解析式,基于中性点理论求出锚杆中性点后锚杆界面剪应力解析式,从而得到锚杆整个界面剪应力及轴力表达式。研究表明:1)通过锚杆界面应力解析式得到影响全长粘结型锚杆界面剪应力的因素有锚杆和锚固剂直径、弹性模量和围岩测压系数;2)水平地应力是影响围岩变形的主要因素,相关研究成果可以为锚杆支护设计提供一种理论依据。

To study the interaction relations,the deformation of surrounding rock and bolt for roadway surrounding rock deformation parameters,based on the deformation of surrounding rock,the analytical expression of shear stress at the interface of the full-length bonded bolt in roadway caused only by the deformation of surrounding rock is deduced.By analyzing the influencing factors of interfacial shear stress of bolt,according to the theory of neutral point,the bolt can be divided into two segments,neutral point before and after the neutral point,will cause the deformation of surrounding rock deformation of surrounding rock and the internal force in the form of strain energy substitution,and the bolt shear stress analytic expression before neutral point,based on the theory of neutral point and the anchor bolt after neutral interface shear stress analytic expression,anchor the whole interface shear stress and axial force expression is obtained.The results show that:1)The factors affecting the interface shear stress of the full-length bonded bolt include the diameter of bolt and anchoring agent,elastic modulus and surrounding rock pressure measurement coefficient;2)Horizontal ground stress is the main factor affecting the deformation of surrounding rock,and relevant research results can provide a theoretical basis for bolt support design.