Abstract: In order to explore a new technology of environmental protection and efficient rock breaking,a composite blas ting method is formed by combining the rapidity of explosive heat release with the phase change of dry ice.Through the model blasting test,the rock breaking capacity of explosive-dry ice composite blasting is systematically studied,and the block distribu tion and fracture field evolution law are emphatically analyzed.The test results show that the dry ice sublimates rapidly after the detonation of the explosive,and the degree of rock fragmentation increases significantly with the synergistic effect of the explo sive.With the increase of the amount of dry ice,the fractal dimension of rock mass fragmentation shows an upward trend,indi cating that the explosive-dry ice composite blasting can effectively enhance the uniformity of rock mass fragmentation.The in corporation of dry ice increases the production of explosive gas,drives the development of fractures,and significantly expands the scope of effective crushing zone.The explosive-dry ice composite blasting realizes the cascade release and effective utiliza tion of energy through the synergistic effect of chemical energy release and physical phase change expansion of explosion,and has the technical advantages of efficient rock breaking and environmental friendliness.This study provides practical reference for the new development in the field of mine blasting.

Key words: blasting,dry ice,explosive,phase change,block distribution