The cracking technology by liquid CO2 transient has been increasingly applied to rock excavation. The rapid acquisition and systematic characterization of the fragmentation distribution have important application value for rapidly evaluating the effect of liquid CO2 transient cracking under field conditions. In order to solve the problems of incomplete information acquisition

complicated operation

and large workload

a new method is proposed in this paper that combines the UAV camera technology and the MIPS image processing technology to comprehensively and quickly obtain the broken rock feature information (area

perimeter

maximum chord length

etc.) and apply it to liquid CO2 transients. On this basis

through the comprehensive analysis of the inhomogeneity and curvature characteristics of the block information

the fractal theory was used to describe the distribution of liquid CO2 transient fragmentation

and the fractal dimension D was applied to quantitatively characterize the fragmentation distribution of the broken rock. The field experiment results show that the “UAV camera + MIPS image processing” technology could extract the rock block information quickly

accurately

and completely. Moreover

the fractal dimension could better characterize the distribution of split block. The larger the fractal dimension was

the higher the proportion of small pieces was

and otherwise the lower it was. This study provides a new important technical support for timely analysis and rapid adjustment of borehole scheme and corresponding technical parameters.