The elastic modulus of rock reflects its ability to resist deformation and its energy accumulation. The traditional method for measuring the elastic modulus of rock is laboratory compression testing. The results of laboratory compression tests cannot reflect the mechanical properties of rock under real environmental conditions. Therefore, the relationship between rock compressive strength and drilling parameters is studied in this paper on the basis of the specific energy required for the fragmentation of unit volume rock. Drilling tests on different types of homogeneous rocks were conducted using the intelligent detection and anchoring system of underground engineering, and the variation law of the rock elastic modulus with respect to the drilling parameters is clarified. The rock equivalent elastic modulus drilling prediction models were established.( e t - E eq , e r - E eq and e - E eq models). The validation results of the rock equivalent elastic modulus drilling prediction models revealed that the average difference rates of using the rock equivalent elastic modulus drilling prediction models to predict the equivalent elastic modulus of rocks were 12.60%, 11.72%, and 11.63%; the RMSEs were 0.85 GPa, 0.52 GPa, and 5.01 GPa; and the MAEs were 0.63 GPa, 0.50 GPa, and 4.82 GPa, respectively, which verified the effectiveness of the rock equivalent elastic modulus drilling prediction models. This paper provides a new test method for rapid testing of the elastic modulus of surrounding rock in underground engineering.
Jian et al. (Fri,) studied this question.