Numerical Simulation on Dynamic Response of Drilling Parameters in Loaded Rock Mass

The characterization of the mechanical parameters of rock mass is a basic problem in the field of rock mechanics, and it is also an important basis for surrounding rock classification, stability analysis, and support design in underground engineering. Based on the engineering background of pressure relief drilling in Guotun Coal Mine, this paper carries out an engineering test while drilling. The numerical simulation method is used to explore the influence of different lithology rocks, different control conditions, and different confining pressure conditions on the parameters while drilling and to study the variation in drilling time, drilling depth, drilling rate, and revolution speed. The results show that under the same control conditions, the drilling rate of coal, mudstone, sandy mudstone, and siltstone are in the order of coal > mudstone > sandy mudstone > siltstone. For similar rock specimens, when the thrust is fixed, the drilling rate increases with the increase in the revolution speed, and when the revolution speed is fixed, the drilling rate increases with the increase in the thrust. When the rock specimen is in different confining pressure states, the drilling rate decreases with the increase in confining pressure, and the torque increases with the increase in confining pressure. This study provides a scientific basis for the realization of in situ rapid and effective measurement technology for the rock mechanical parameters of coal and rock mass, which is helpful for improving the measurement accuracy and efficiency and promoting the safe and efficient mining of coal mines.