# Numerical Simulation on Dynamic Response of Drilling Parameters in Loaded Rock Mass
###### Abstract  
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. d 2025  
mechanics parameters and drilling parameters through theoretical analysis and laboratory tests and put forward a variety of prediction models for engineering rock mass quality evaluation. It is worth noting that most of the current prediction models based on drilling parameters are semi-empirical models, which have problems of reliability and unclear applicable conditions. Laboratory tests also face problems such as being time-consuming, incurring high costs, and producing results that are easily affected by the non-uniform characteristics of rock samples. In contrast, the numerical simulation software has obvious advantages. It can quickly set different parameter combinations and can complete a large number of simulation calculations in a short time, so as to quickly obtain the results under different conditions. In addition, by constructing a detailed model, the numerical simulation software can also comprehensively analyze the changes in various drilling parameters related to the drill bit during the drilling process, providing more abundant and detailed data support for the research work [14; 15; 16; 17; 18]. In terms of numerical simulation, [PERSON] [19] et al. used ABAQUS 2014 software to simulate the rock fragmentation process of PDC cutters and compared the simulation results with the experimental data. The results show that the simulation results are in good agreement with the experimental results. [PERSON] et al. [20] used numerical simulation methods to conduct in-depth research on the rock breaking process of the drill under static and dynamic loads. The results show that the rock breaking efficiency under dynamic loads is significantly higher than that under static loads. [PERSON] [21] based on the finite element analysis software LS-DYNA, the rock breaking simulation analysis model of a PDC bit is established, and the interaction law between the drilling rate, bit speed, drilling pressure, and torque is obtained. [PERSON] et al. [22] studied the relationship between the vibration characteristics of the drill pipe and the rock strength during the drilling process for the roof anchoring hole in the coal roadway by the numerical simulation method and concluded that the drilling vibration characteristics are important information for identifying the roof strata. [PERSON] et al.