A new bond-degradation creep model has been developed to accurately predict the failure and fracture evolution of deep granitic rocks under high-stress conditions. This innovative approach combines the variable radius particle clump dynamics to create more reliable models than those available previously. Conducted by researchers from Liaoning Technical University and other institutions, this research is significant for enhancing safety measures and operational efficiency during deep mining operations.
The study, published on February 25, 2025, examines granite sourced from the ${-1080 ext{ m}}$ prospecting roadway of the Xincheng Gold Mine, located at extreme depths where rock behavior switches considerably from predictions based on traditional models. Creep behavior, which refers to the time-dependent deformation of rocks subjected to constant stress, remains one of the major challenges faced during excavations at these depths.
Currently, many models focus on stress corrosion processes or linear strength mobilization, assuming rock behaviors remain static during stress applications. Researchers have found these approaches often fall short of delivering accurate predictions of fracture initiation and evolution. The new bond-degradation creep model offers notable improvements by enabling real-time adjustments to the bond parameters governing rock mechanics.
To verify the effectiveness of their model, the team conducted extensive laboratory tests and technologically advanced simulations, employing the particle flow method for granular material representation. The results demonstrated the variable radius clump model's superior performance, improving the tension-compression ratio of rocks and minimizing discrepancies between modeled and observed behaviors.
According to the authors of the article, "The variable radius clump modeling method could reflect mechanical properties of the tension-compression ratio of different types of rocks by adjusting the radius ratio of the clump particle.” The researchers also emphasized the model's ability to control creep rates, which they attribute to variable activation of bond parameters during strain.
The findings revealed significantly shorter creep failure times and yielded microfracture characteristics more aligned with field data than existing models. Enhanced strain predictions were evident during accelerated loading phases, indicating the bond-degradation model's capacity to mirror real-world geological behaviors accurately.
Future research may expand on these insights, exploring how different environmental factors impact creep behavior and assessing the economic benefits of implementing these findings across other deep mining projects. The insights gleaned from this study provide invaluable contributions to geological engineering and rock mechanics, enhancing both safety protocols and structural integrity.
Overall, the bond-degradation creep model, based on variable radius particle clump methodology, could redefine standard practices for assessing rock stability, making significant strides toward advancing techniques utilized across the deep mining industry.