Timeliness of collinear crack propagation in rock mass

There are a large number of non-penetrating collinear cracks in the rock slope an open-pit mine. The timeliness mass is problem that cannot be ignored terms engineering safety. Based on superposition principle and fracture mechanics, stress intensity factor crack tip with fractures under biaxial compression was calculated this study. A mechanical model propagation constant load established according to Charles equation. effects loading time, penetration rate, dip angle along direction bridge were analyzed theoretically. variations time examined using LS-DYNA creep numerical model. results show growth rate changes three stages over progressing through stable stage, decreasing abrupt stage. higher larger inclination cause mass. When exceeds 74% or about 60°, expansion directly enters penetrated. theoretical analysis close agreement work, which validates proposed age for masses fractures.