# Numerical Simulation Analysis Method for Rockburst Control in Deeply Buried Caverns
## 6 Conclusions  
According to the principle of active and passive rockburst control measures, the iterative of the three-dimensional elastoplastic damage finite element variable damage stiffness method is used to effectively simulate the rockburst control effect of borehole stress relief and anchor rod reinforcement support. The use of energy theory and strength theory to assess the effectiveness of borehole stress relief and anchor rod reinforcement support fully illustrates the mechanism of active and passive control of rockburst. Through the simulation analysis of examples of underground tunnel excavation engineering, the following conclusions can be summarized:  
(1) The proposed implicit borehole element can effectively simulate the active effect of borehole stress relief on rockburst control. This method embeds the borehole element within the rock mass element. This not only facilitates the arrangement of borehole elements but also makes finite element modeling more convenient. Additionally, it allows for a reasonable reflection of the effect of different drilling directions on stress release. According to the concept of equivalent node load transfer in borehole stress relief, it effectively describes the changes in the external environment caused by relieving stress in the borehole. It also reasonably reflects the reduction in energy accumulation and stress concentration in the rock mass due to drilling. However, it is important to note that drilling only releases a portion of the energy stored in the rock masses. Therefore, the control of rockburst is relatively limited, indicating that boreholes are only effective in mitigating mild rockburst incidents;  
(2) The proposed implicit anchor rod element can effectively simulate the stiffness reinforcement effect of the anchor rod on the surrounding rock and the passive resistance effect to prevent rockburst. Since the anchor rod element is implicit in the rock mass element and both are modeled separately, the anchor rod element provides great convenience for adjusting the anchor rod arrangement and support scheme. The use of column elements to simulate the support effect of anchor rods can reflect the overall reinforcement effect on the surrounding rock. By combining anchor rod consolidation and hanging into an arch, the overall stiffness of the surrounding rock is improved, the internal resistance of the surrounding rock is increased, and the occurrence of rockburst is effectively reduced. This method accurately reflects the interaction between the anchor rod and the surrounding rock. The anchor rod connects the surrounding rock, forming a cohesive unit that helps to prevent the release of energy in the rock mass. The surrounding rock undergoes deformation and the resistance is applied in reverse to reduce stress concentration, prevent the sudden release of energy, and mitigate rockburst occurrences. Since the effect of anchor rod reinforcement on the surrounding rock is significant, anchor rod support can effectively control strong rockburst;  
(3) The use of three-dimensional elastoplastic damage finite element simulation for borehole stress relief and anchor rod support can effectively control rockburst, both actively and passively. This method accurately reflects the mechanisms behind these control measures. Using strength theory and energy theory to analyze and evaluate the rockburst  
Figure 8: Stress distribution of anchor rods. control situation of borehole stress relief, both types of theoretical analyses indicate that the active control measure of borehole stress relief only partially improves the external environment of rockburst. Furthermore, these analyses suggest that it can only effectively control some light-grade rockburst. As for anchor rod support, there are slight differences in the rockburst control effects between the two types of analyses. The effectiveness of anchor rod support is demonstrated, indicating that it is a passive control measure that alters the internal factors of rock mass resistance to rockburst.