The paper reviewed the experimental research progress of prefabricated drilling and high stress real-time drilling in analyzing the mechanism of drilling pressure relief(DPR)for preventing rockburst disasters from the perspectives of macroscopic(mechanical behavior characteristics, failure characteristics, energy evolution)and microscopic(crack evolution), and elaborated on the rationality and effectiveness of DPR for preventing rockburst disasters. Theoretical research and experimental analysis had confirmed that DPR was a key technology for relieving high stress and high energy in deep surrounding rocks, providing a reference for optimizing the application of DPR to prevent rockburst. High stress real-time drilling test method was a more scientific new research method that revealed the internal mechanism of DPR to prevent rockburst. Based on this, six development directions had been proposed for the experimental research on the mechanism of rockburst induction and the current technical conditions of multifunctional testing systems to analyze the mechanism of DPR to prevent rockburst: developing high-stress drilling rig test equipment compatible with true triaxial test systems; considering disturbance factors in high-stress real-time DPR simulation tests; simulating real-time DPR test after excavation of deep tunnels(roadway)("3D six-sided loading-single-sided unloading-real-time DPR" test); constructing an analytical model for the energy evolution of surrounding rock under 3D high stress real-time DPR; exploring the relationship between the spatial size effect of pressure relief drilling and the stress field and internal energy dissipation mechanism of surrounding rock; establishing a computational model for rockburst prevention by DPR in large-scale high-stress surrounding rock based on numerical simulation software.

In order to probe into the similarities and differences of the stress-deformation law and the reinforcement effect of shield tunnel strengthened with corrugated steel under complex stress paths, a refined model of three-ring staggered joints was established based on the finite element software MIDAS GTS NX, the effect of corrugated steel reinforcement was evaluated from the angle of convergent deformation, corrugated steel stress and plastic deformation of segments before and after reinforcement, the stress and deformation evolution of shield tunnel strengthened with corrugated steel under loading and unloading conditions were analyzed. The results showed that the distribution of the maximum convergent deformation was different in the complex loading environment. The waist was the main part of the loading, and the top and bottom was the main part of the unloading under unloading, the effect of corrugated steel reinforcement was better than that under surcharge loading, and the maximum reinforcement efficiency could reach 70%, the convergent deformation and the stress development of corrugated steel with different plate thicknesses were similar and showed a linear increasing trend, while corrugated steel could effectively delay the plastic development of concrete, however, the ability of stagger suppression between rings under unloading condition was weak.

Based on rheological mechanics and viscoelastic mechanics, a theoretical model for the coupling of prestress loss of anchor and creep of rock was established. Considering the influence of prestress loss when the prestressed anchor was used to reinforce rock mass, the creep equations of stable creep rock and unstable creep rock were derived, and the formula for calculating prestress of anchor with time was obtained. The results showed that the anchor prestress loss was faster in the period of completion of anchor tension; then the rate of prestress loss was gradually reduced and finally stabilized, and the creep of rock also became stable. By comparing the calculated results with the experimental results in existing literature, the curves of the two were consistent, which verified the correctness of the model. The comparison between the variation of anchor cable prestress at Jinping Hydropower Station and the calculation results of the theoretical model proves the accuracy of this research model applied to engineering examples. The theoretical analysis results established in this paper considering the coupling of anchor cable prestress loss and rock mass creep have a wider application range than previous coupling models, which is not only applicable to stable creep rock, but also to unstable creep rock. The warning of abnormal changes in anchor cable anchoring force and the long-term safe operation of slope engineering have extensive engineering application value.