The weakening of physical and mechanical properties of weathered granite often has a great impact on engineering stability. Therefore

it is of great significance to study the failure characteristics of granite with different weathering degrees. Combining the qualitative description of the core characteristics and the quantitative evaluation index of wave velocity ratio

the granite rocks collected from the reservoir area of Wuyue Pumped Storage Power Station in Henan Province were divided into three groups: slightly weathered granite

weakly weathered granite and strongly weathered granite. The fragments generated from granite rocks during uniaxial compression tests were collected

and their quality and scale characteristics were analyzed. Then

the corresponding relationship between fragment fractal dimension and wave velocity ratio was established. Meanwhile

the MATLAB software was employed to calculate the fractal dimension of the cracks on the main rupture surface. The results show that weathered granite rocks mainly produce coarse grain fragments and the proportion of fragments in coarse group gradually increases with the increase of weathering degree. Strongly weathered rocks produce blocky fragments in a small proportion and have a narrow range of the length-thickness ratio

indicating weak dynamic failure characteristics. Besides

their fragment shapes are single and mainly have plate-like structure. With the decrease of weathering degree

the proportions of blocky fragments increase and the dynamic failure characteristics become more apparent. The fractal dimensions of fragments have an increasing trend with the increase of the wave velocity ratio. Compared with the fragment quality

width and thickness

the fragment quantity and length are the main factors affecting the fractal dimension and are also the main parameters reflecting the fractal characteristics of granite with different weathering degrees. Moreover

the crack fractal dimensions of rupture surface for weakly and slightly weathered granite rocks increase significantly with the increase of wave velocity ratio

while for strongly weathered granite rocks there is no obvious change. It implies that the cracks of weakly and slightly weathered granite rocks have a higher degree of self-similarity

more complex structure and require more energy for their initiation and propagation