Study On Mechanism Of Rock Damage And Crack By Explosion Loading

With the rapid development of economy and construction in our country, the blasting technology has been used widely in many industries, such as: water conservancy, electricity industry and transportation, which has brought great economic and social benefits. On the other hand, despite the great progress made hi blasting technology, there still exists many problems to be resolved.On the basis of theory of fracturing mechanics and damage mechanics, the mechanism of damage and fracture by explosion load has been analyzed and studied deeply. And the calculation of blasting damage in rock is explored further by using the combination of the current model for blasting damage and the simulating blasting experiment.In the light of the blasting mechanics, rock damage by blasting can be studied in two stages: 1. the dynamic damage stage under explosion stress waves. 2. the quasi-static damage stage under the quasi-static stress field produced by gas from explosion. Finally, the general model for blasting damage and fracture is gained.In the thesis, a gas-driven fracture propagation and damage localization at the crack tip model during explosion products are proposed. And with the introduction of the Modulus of Elasticity from Budiansky method, the general damage model of rock blasting is established in the paper.By use of the ultrasonic wave, rock damage and fracture mechanism and the fragmentation process during blasting are studied, and the theory presented in the paper has been proven.