## 6 Conclusions  
This study proposes a method for assessing the rock burst risk associated with roadway tunneling by incorporating variation in the mechanical parameters of the surrounding rock using 3 DEC numerical simulations and the principle of stress gradient difference. The main conclusions are as follows:  
1. Rock burst risk can occur even with relatively low kinetic energy within the coal mass, according to the analysis of the displacement and kinetic energy patterns in the roadway side during tunneling. Areas adjacent to the side of the roadway exhibit a higher susceptibility to stress disturbances induced by tunneling, leading to an increased stress gradient difference in the coal mass near the side zone, thereby resulting in burst phenomena. The released kinetic energy and rock burst risk are associated with the ground stress change.
2. With the consideration of the effects of variation in the mechanical parameters of coal mass on rock burst, a relationship between coal mass mechanical properties  
Figure 10: Plots of \(D_{gc}\) curves under different COVs for coal mass mechanical parameters.  
and rock burst is established. This relationship elucidates the connection between rock burst risk during roadway tunneling and the mechanical parameters of coal mass, indicating that the varied values of these parameters significantly influence the induction of rock burst risk.
3. A clear linear relationship exists between the coefficient of variation (COV) of coal-mass parameters and the occurrence of rock burst in roadway sides. The variation of the COV in the internal friction angle and cohesion exhibits positive and negative correlations with burst risk, respectively. An increased COV in cohesion heightens the likelihood of significant deformation in the side during roadway tunneling, which, consequently, elevates the rock burst risk.  
However, the study did not carry out an in-depth investigation of roadway damage or eruption under more complex geological conditions in the surrounding coal and rock variation. Future investigations should incorporate stochastic field theory to quantitatively evaluate rock burst risk and conduct reliability analyses of tunneling processes influenced by the variable spatial parameters of coal seams. This methodology has the potential to yield theoretical and technical insights for the early warning and prevention of dynamic hazards associated with deep mining.  
Conceptualization, Y.Y. and N.L.; methodology, Y.Y. and N.L.; software, Y.Y.; validation, N.L.; data curation, N.L.; writing--original draft preparation, Y.Y. and N.L.; writing--review and editing, Y.Y; visualization, Y.Y.; supervision, N.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China under Grant No. U21A20110, the National Natural Science Foundation of China under Grant No. 5204193, and the China Postdoctoral Science Foundation under Grant No. 2020M681975.  
Not applicable.  
The data that support the findings of this study are available from the corresponding author upon reasonable request. The data are not publicly available due to laboratory policy.  
The authors are grateful to the editors and the anonymous reviewers for their insightful comments and suggestions.  
The authors declare no conflicts of interest.