Numerical Investigation on Fracture Mechanisms and Energy Evolution Characteristics of Columnar Jointed Basalts With Different Model Boundaries and Confining Pressures

To reveal the mechanical mechanisms and energy release characteristics underlying progressive failure of columnar jointed basalts (CJBs) with various model boundaries confining pressures, by combining meso-damage mechanics, statistical strength theory, continuum inhomogeneous CJB models different dip angles to column axis are constructed. In cases plane stress, strain, between stress gradual fracture processes CJBs simulated under pressures acoustic emission (AE) rules obtained. The results show that: 1) in case process along direction I orthogonal axis: at initial stage loading, vertical joints transverse specimen damaged. Then, more columns upper middle part cracked; 2) parallel area damaged broken top increases crushing degree intensifies; 3) for AE accumulation before peak is higher than strain state axis. Meanwhile, axis, this value becomes larger when changing from state. These achievements will certainly improve our understanding mechanism evolution provide valuable insights into instability precursor CJBs.