Splitting Criterion of Grouting Bore-hole Wall and Study on Numerical Simulation of Crack Propagation

摘要

The situation that the grouting borehole doesn't intersect with natural fractures of rock masses is often met in practical grouting project. Hence, it's very necessary to discuss whether the rock masses around borehole will split under the grouting pressure and the corresponding splitting orientation. After the splitting crack finishes propagation, we can estimate whether it will penetrate with original fractures, and it's favorable for grouting theory analysis and numerical simulation and so on. According to this, the splitting criterion and splitting orientation are proposed with and without considering ground stress, respectively. In the meantime, under the situation of splitting, the singularity of crack-tip's stress field is simulated by 6 nodes singular isoparametric element through secondary development of large-scale finite element analysis software-ANSYS. The stress intensity factor is introduced and the propagation of the splitting crack is simulated to obtain the final propagation length, which has significant guiding meaning to grouting theory and the practical grouting projects.