Research on the interaction of rock-mass with multiple cracks under seepage pressure

In actual geotechnical engineering, many rock-mass which contains mang cracks, are in water environment. These adjacent cracks would interact with each and the seepage pressure changes cracks status and also affects the stress state in rock. According to the theory of fracture mechanics, the mechanical model of rock-mass which including multi-crack under the action of seepage preasure was set up. Based on principle of superposition, the formula for calculating stress intensity factor was built. The stress intensity factor of cracks are calculated in different conditions, such as different crack distance, different crack angle and different seepage pressure. The results suggest that, the crack tip´ stress field caused by interaction of cracks has significant influence if distance between two cracks is short. The influence of adjacent cracks interaction is related to the distance between two cracks, with the crack distance increases, the SIF is close to a fixed value which is calculated without considering the interaction between cracks. The results also show that the seepage pressure significant affects the stress field near crack tip and the stress intensity factor K_I increases along with seepage pressure increasing. This research results can provide a theoretical basis to study the fractured rock mass failure under seepage pressure condition.