Relationship model for the drilling parameters from a digital drilling rig versus the rock mechanical parameters and its application

Measuring rock mechanical parameters is an essential step for support design in an underground project. To quickly obtain the surrounding rock mechanical parameters at a construction site in real time using a digital drilling rig, a quantitative relationship between the drilling parameters and rock mechanical parameters should be defined. In this paper, based on the fracture characteristics of rock cutting, a relationship model for the drilling parameters of the digital drilling rig versus the rock mechanical parameters (DP-RMP model) is created. Based on the multi-function rock drilling test system developed by the authors, rock drilling tests for different drilling parameters and theoretical results are compared and analysed to prove the validity and accuracy of the DP-RMP model. Additionally, the influence laws of the cohesion and internal friction angle on the rock cutting drilling torque are investigated. Drilling parameters from the digital drilling rig-based rock mechanical parameter inversion method is proposed; the feasibility of this method is verified by rock drilling test results. The study provides a theoretical basis for quickly obtaining the rock mechanical parameters using drilling parameters on site in real time.