Process And Mechanism Of Rock Rupture Induced By Dynamic Disturbance

Because of its own weight and the earth structure, the underground rock mass is in the high ground stress state. Under the condition of mine excavation and blasting, the original state of rock mass, such as deformation, stress and energy can be changed, which make it difficult to determine the stability of the rock. Therefore, it is very important to carry out rock dynamic disturbance simulation test to analyze the development state of rock under instantaneous dynamic disturbance.The rock mass, under quasi-static stress and strain state, can maintain a stable state for a long time, and exhibit rheological properties, during this period dynamic transient disturbance can break the original steady state and induce the occurrence of rock failure. Based on this, this paper adopts the method of uniaxial compression, and carries on the simulation experiment of high stress dynamic loading to rock. The experiments show three different test results:1 under the state of high stress stability, dynamic disturbance directly lead to the failure of rock;2k rock is not destroyed immediately by dynamic disturbance, but develop to brittle destruction slowly, known as delayed brittle failure;3 in the process of dynamic disturbance rock is not destroyed and after the subsequent long time remained stable and shows no sign of damage.In the process of stability, the rock is in the coupling state of creep and stress relaxation, and evolves to brittle failure. The test data are carefully sorted out, and the whole process curve of rock stress and deformation is obtained. The experiments show that the initial loading stress and deformation are the primary conditions that can cause the failure of the experiment, and the dynamic disturbance is an important condition of the induced damage. Over the state limit the rock failure will occur under dynamic disturbance, the lower limit value is about 80% of the single axis limit; the macroscopic cracks are mainly divided into two kinds: one is "Y" type half-splitting crack along the vertical direction of the symmetrical section, and the other is a "X" type crack along the diagonal line; the change rate of rock stress and deformation imply the corresponding critical power law characteristics, and the initial period has the logarithm power law singularity of the approximate-4/5 power, and the later period has the logarithm power law singularity of the approximate-1 power; the stress relaxation dominates the energy release, and the creep phenomenon is the dominant role of energy storage; The stability time exerts a power relation with the disturbance load stress, and the test time has a linear relationship with the disturbance residual deformation.