Mechanical behavior of anchored rock with an infilled joint under uniaxial loading revealed by AE and DIC monitoring

The progressive failure of fractured rock affects the stability and safety of rock engineering and has always been a key issue in rock engineering field. As the most common support way, the addition of bolt will change the stress distribution and further effect the failure characteristics of fractured rock. It is of significance to study the failure characteristics of anchored fractured rock for the relevant projects. In this study, digital image correlation (DIC) and acoustic emission (AE) technology were used to study the influence of bolt on fracture behavior of infilled jointed rock under uniaxial loading. The results show that the addition of bolt makes the pre-peak ductility more obvious. The enhancement degree of bolt on mechanical parameters decreases with the variation of joint angle. The principal strain field shows that the addition of bolt can effectively inhibit the propagation of wing crack and anti-wing crack, which leads to the failure of anchored specimen tends to shear failure. The RA-AF distribution of anchored specimens also shows that the scattered points shift to the shear signal area in the plastic stage and post-peak stage. In addition, for anchored specimens, b-value corresponding to the peak stress is higher than b -value corresponding to the initial loading, indicating that there exists an obvious anchoring effect of the bolt in the plastic stage and post-peak stage.