Study on mechanism of controlled blasting and damage evolution of rock mass under high ground stress
To study the damage and crack evolution of deep-hole controlled blasting under high ground stress,the deep-hole loosening controlled blasting gas permeability increase project of Huainan Pansan Mine is used as the engineering background.The influence of high ground stress on rock controlled blas-ting crack evolution is explored based on the theoretical analysis and numerical simulation of controlled hole guidance,stress wave propagation,and rock stress around controlled holes underground stress,tak-ing into account the fractal dimension of rock blasting cracks.The results show that the controlled hole has a certain directional effect on the expansion of blast-induced cracks,the effect that is affected by the high ground stress in deep mining areas.When the direction of the line connecting the controlled hole and the blasting hole is consistent with the direction of the maximum principal stress,the directional effect of blasting can be optimized;at the beginning of detonation,the controlled hole provides a free surface for the blasting hole,and reduces the minimum resistance line.With the influence of ground stress,the crack expansion direction follows the maximum principal stress direction,further generating rock damage between the blasting hole and the controlled hole.Finally,by analyzing the evolution and fractal dimension of blasting cracks under different ground stress conditions,a prediction model for crack fractal dimension D and damage amount w is established,which can predict the degree of rock damage under high ground stress.
high ground stressrock blastingfractal dimensioncontrolled blastingnumerical simulation
万方数据
维普
