## 5 Conclusions  
This paper uses ABAQUS software to simulate and analyze the rock-breaking process of diamond-impregnated drill bits and study the changing rules of rotation speed, drilling speed, drill bit size and confining pressure on thrust force and torque.  
Considering the influence of drilling speed and rotation speed on thrust force and torque during drilling, the changing rules of drilling parameters on thrust and torque are obtained. This can reduce unnecessary energy consumption, improve drilling efficiency and reduce costs. When the rotational speed is fixed, the thrust and torque are linearly positively related to the drilling speed. As the rotation speed decreases, the slope of the relationship curve between thrust force and torque and drilling speed increases. When the drilling speed is constant, as the rotational speed increases, the thrust force and torque decrease as a power function.  
When the drilling speed is constant, the larger the drill bit size, the greater the thrust force and torque. When the rotational speed is constant, the larger the drill bit size, the greater the thrust force and torque.  
When the inclination angle of the structural surface is 45\({}^{\circ}\) and 90\({}^{\circ}\), the thrust force and torque both decrease with the increase in the thickness of the structural surface. The thrust force and torque decrease sharply during the drilling process from not containing the structural surface to including the structural surface. The drilling results of soft and hard interbedded rock masses show that whether it is a transition from soft rock layer to hard rock layer, or from hard rock layer to soft rock layer, the relationship curve of thrust and torque can identify the transition process.  
Thrust force and torque increase with increasing confining pressure. The thrust force and torque under the action of hydrostatic pressure increase with the confining pressure to a greater extent than those under the bias pressure. This paper uses numerical simulation software to simulate the dynamic process of the drill bit drilling into the rock, which can reduce the cost of actual testing and drilling.  
**Author Contributions:** Conceptualization, X.L. and H.K.; methodology, H.K.; validation, X.M. and M.H.; investigation, X.L.; writing--original draft preparation, X.L. and M.H.; writing--review and editing, X.M. and M.H.; funding acquisition, M.H. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This study is sponsored by the National Natural Science Foundation of China (Grants No. 42177158, 11902249 and 11872301), Key Research and Development project of Shaanxi Province (No. 2022 SF-412), Education Bureau of Shaanxi Province in China (Grant No. 20 JS093). Opening fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology (Grants No. SKLGP2022K005). Open subject of Urban Geology and Underground Space Engineering Technology Research Center of Shaanxi Province (2022 KT-01). The financial support provided by this sponsor is greatly appreciated.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The data used to support the findings of this study are available from the corresponding author upon request.  
**Conflicts of Interest:** The authors declare no conflict of interest.