## 3 Testing Results Analysis
### Total Displacement Analysis  
In order to further analyze the mechanical mechanism of rock mass fracture in the process of slab buckling rockburst, one image is intercepted at different time periods, as shown in Figure 6, and the corresponding coordinate position is shown in Figure 4. Figure 7 presents the total displacement contours in the process of slab buckling rockburst. It can be seen from the figures that under different stresses, the average value of total displacement of the tunnel surrounding rock increases from 0 mm to 4.05 mm, and the maximum value increases from 1.92 mm to 8.1 mm. In the early stage of deformation (\(t<458\) s, \(\sigma_{\rm v}<32.1\) MPa, \(\sigma_{\rm h}=28.1\) MPa), the change in the total displacement of the tunnel is mainly concentrated in the outer surface and inner wall of the right arch roof and spandrel and left arch footing of the tunnel, while the rest of the position is basically unchanged. Due to the compaction of primary cracks and pore stress caused by small deformation Figure 7a-c, the above parts are the common stress concentration areas of the horseshoe-shaped tunnel. With the increase in top load (\(\sigma_{\rm v}=36.9\) MPa-80.8 MPa, \(\sigma_{\rm h}=28.1\) MPa), although the total displacement of the tunnel increases gradually, the changes in the spandrel, arch footing, and haunch are more obvious than those of the arch roof and arch bottom. The maximum value of total displacement of the tunnel extends from the spandrel to the haunch on  
Figure 4: Stress–time distribution characteristics of the slab buckling rockburst test. the right side and from the arch footing to the haunch on the left side Figure 7d-m. It can be seen from the direction of the displacement vector Figure 7m that tension cracks appear on the left and right sides of the tunnel. In the first rockburst ejection Figure 7n, the displacement field of the tunnel surface basically shows the fracture characteristic of bilateral symmetry. The total displacement change of the tunnel is highlighted in the right spandrel, haunch, and arch footing, followed by the left spandrel, haunch, and arch footing; the arch roof and arch bottom show smaller changes. In the second rockburst ejection (Figure 7o), the damage area of bilateral symmetry in the displacement field of the tunnel surface is further expanded, and the peak range of the total displacement is further expanded; however, the displacement value of the right spandrel and haunch are smaller than those of the first rockburst ejection. It shows that the slab buckling rockburst has attenuation characteristic during the process of rockburst. In addition, through the comparison of the deformation rate before and after the initial formation of the slabbing structure, we can draw a conclusion that the deformation rate after the initial formation of the slabbing structure until the occurrence of rockburst is about five times higher than that of the formation process of the slabbing structure. It shows that the slabbing structure will undergo a long-term incubation process before formation, and once the slabbing structure is formed, it will accelerate the occurrence of rockburst. Therefore, for the control of this type of rockburst, on the one hand, attention should be paid to avoiding the formation of slabbing structures; on the other hand, if there is a formation of slabbing structures, corresponding prevention and control measures should be taken. Analysis of Rock Mass Rupture Parameters and Morphological Characteristics of Pits in Rockburst Disaster  
The precise and quantitative study of some key problems, such as the initial location of cracks, the propagation of existing source fractures, and the formation mechanism of pits, is of great value for accurately understanding the mechanism of rockburst. Therefore, this paper selects 18 experimental images at different times and imports them into Auto CAD 2019 after binarization processing.