Numerical Simulation Analysis Method for Rockburst Control in Deeply Buried Caverns

Abstract

Investigating the mechanism and measures of controlling rockburst in deeply buried underground caverns is a prerequisite for ensuring the safety of personnel, reducing the damage to construction equipment caused by the rockburst, and making the project economical and efficient. Efficient analysis methods for evaluating rockburst control in underground caverns are crucial for qualitatively selecting rockburst control methods and quantifying the effectiveness of rockburst measures. Based on the mechanism of energy accumulation in rock mass and the occurrence of rockburst as well as the active methods for controlling rockburst, we propose a mathematical model for simulating borehole stress relief using implicit borehole elements. In this modeling approach, we combine vector superposition in different borehole directions to analyze the effect of borehole stress relief on improving the external environment of the rock mass. Based on the interaction between the anchor support and the surrounding rock as well as the implementation of passive rockburst control measures, we propose a mathematical model that utilizes the implicit anchor column elements to simulate the reinforcement of the surrounding rock with anchors. By combining system anchors into arches and suspending anchors to reinforce the caverns, the overall stiffness of the surrounding rock can be improved and the stress accumulation can be alleviated. The coordinated deformation between the surrounding rock and the anchor provides support to prevent the rockburst. The effects of two rockburst control measures, borehole releasement and anchor reinforcement, are analyzed using both the strength theory and the energy theory. Engineering examples are provided to illustrate that the use of borehole elements to simulate local stress relief can effectively improve the external environment of the rock mass to control the occurrence of rockburst. Additionally, the mechanism of using anchor column elements in combination with the surrounding rock elements to enhance the overall stiffness of the rock mass and prevent rockburst is explored.

Keywords

• borehole release
• anchor rod support
• implicit element
• rockburst control