Effect of Rheological Mesoparameters on Shear Mechanical Behavior of Joints

Abstract

Under natural conditions, joint failure usually occurs after long-term loading rather than short-term loading. In order to prevent rock mass failure caused by creep behavior, bolt is widely used as a mature and effective reinforcement method. Therefore, it is necessary to consider the rheological effect of bolted joint. In this paper, the particle flow code (PFC) was used to study the effect of mesoparameters on the rheological shear mechanical behavior of joints without bolts and with bolts. The effects of mesoparameters such as Maxwell elastic coefficient $E_{\text{m}}$ , Maxwell viscosity coefficient $C_{\text{m}}$ , Kelvin elastic coefficient $E_{\text{m}}$ , Kelvin viscosity coefficient $C_{\text{m}}$ , and friction coefficient $F_{\text{s}}$ were analyzed. The results show that $E_{\text{m}}$ and $F_{\text{s}}$ mainly affect the instantaneous shear displacement, but have little effect on the rheological shear displacement. However, $C_{\text{m}}$ , $E_{\text{k}}$ , and $C_{\text{k}}$ have little effect on the instantaneous shear displacement, and the sensitivity is mainly reflected in the rheological shear displacement. $E_{\text{m}}$ and $F_{\text{s}}$ mainly affect the instantaneous shear displacement, but have little effect on the rheological shear displacement. However, $C_{\text{m}}$ , $E_{\text{k}}$ , and $C_{\text{k}}$ have little effect on the instantaneous shear displacement, and the sensitivity is mainly reflected in the rheological shear displacement. Compared with the parameter sensitivity characteristics without bolt, the instantaneous shear displacement, shear stiffness, and steady rheological displacement under anchor condition are less affected by parameters, indicating that anchor can reduce the influence of joint parameters.