Optimization criteria for coal rock cutting parameters based on digital rock mechanics

Tunneling is a critical process in coal mining and infrastructure construction, where its efficiency and safety directly impact economic performance and human life protection. However, the optimization of cutting parameters throughout the tunneling process in coal mines still faces many scientific challenges. Moreover, as coal mining advances into deeper areas, the more complex geological environment poses higher requirements for the optimization of cutting parameters. To address the issue of intelligent and efficient optimization of cutting parameters throughout the tunneling process in the digital age, a new solution for cutting optimization in complex tunneling environments by integrating the digital rock mechanics is proposed, which is centered on physical transparency, structural transparency, and stress transparency. To accurately evaluate the mechanical cutting performance of coal and rock, based on the crack tensor theory, the crack structure is quantitatively described in multiple dimensions, achieving a quantitative characterization of the relationship between the crack structure of coal and rock and their cuttability. To solve the problem of multi-tooth cooperative rock breaking of the cutting drum, numerical simulations of multi-tooth cooperative rock breaking were conducted using the digital rock mechanics solver CoBums, revealing the dynamic cutting force and the propagation law of stress waves. To address the lack of intelligent cutting planning in tunneling methods, the dynamic adjustment of cutting process parameters was optimized by integrating multi-source data fusion technology of coal and rock. To tackle the problem of coordinated tunneling and support operations and dynamic adjustment of support parameters, the time-space evolution laws of stress and discontinuous structures of underground coal and rock masses were grasped by using controllable seismic sources and in-situ seismic detection technology, thereby dynamically optimizing the time-space zonal support parameters. To solve the problem of low-disturbance and high-efficiency tunneling technology in deep underground tunnels, through laboratory and field-scale studies on low-disturbance cutting and rock breaking, the relationship between tunneling disturbance and stress direction was clarified, providing guidance for reducing the risk of dynamic disasters. Digital rock mechanics has made significant advances in coal rock cuttability, multi-cutter cooperative rock breaking, low-disturbance cutting, and support optimization, providing technical support for improved tunneling efficiency, disaster prevention, and intelligent development. This approach shifts the optimization of cutting parameters from experience-based judgment to automated, digital, and intelligent methods.