Through analyzing the existing definitions of damage variables

we try to use the fractal dimension as a characteristic of the rock damage variable and establish the relationship between fractal dimension and damage degree. According to the calculation method of box-counting dimension and digital image storage principles

to compile the simple digital image of a box-counting dimension algorithm based on Matlab. Combining with practical project of blasting

the digital panoramic borehole camera system is taken for field-test. Through extracting the crack from images of the before explosion and post-explosion of blasts rock

then some graphics processings are made to get the fractal dimensions corresponding to cracks. Finally

damage increments under the action of blasting are determined. The results show that the using fractal dimension to describe the damage of rock

overcomes the disadvantages of other definition methods which involve too much rock characteristic parameters

so as to explore a new way to study the damage degree and evolution process of rock damage.