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Rock excavation is a dynamic process where rock is dynamically loaded by mechanical cutting tools. Previous researches have shown that rock strength in dynamic loading is greater than that in static loading. However, existing prediction models for mechanical excavation of rock do not take into account the dynamic features of the rock. This issue has the potential to deliver misleading outcomes when estimating cutting performance and assigning an equipment for excavation work. The mechanical cutting issue was explored from a dynamic standpoint in this paper. To begin, the dynamic level of mechanical cutting was studied with multiple attempts and was shown to be at intermediate strain rate (ISR). Then, experiments were designed to determine dynamic mechanical properties via a loading device powered by a non-explosive powder reaction capable of creating dynamic loading in the ISR range. Furthermore, numerical simulation of pick cutting using the finite element technique was carried out, incorporating dynamic and quasi-static parameter settings. Also, a laboratory linear cutting test was conducted under various cutting configurations to validate the numerical results. The numerical simulation with quasi-static inputs was shown to be less accurate than the modeling with dynamic inputs. The simulation with dynamic inputs matches the laboratory findings closer by exhibiting a narrower margin. Thus, this study offers a unique view of evaluating mechanical excavation issues from a rock dynamic perspective. [ABSTRACT FROM AUTHOR]

This paper presents a study of the mechanical behaviour of rock under dynamic compression loading at intermediate strain rate (ISR). A series of laboratory tests were carried out to obtain dynamic uniaxial compressive strength by using a non-explosive powder reaction loading apparatus that was able to generate loading in the ISR range. It was found that the strength of granite and sandstone specimens increases at the ISR range. The results were discussed with a comparison with other findings from multiple references. In general, strength increases linearly at the lower rates and rises significantly at higher rates. Within the ISR range, the tendency is not consistent. Further understanding of rock behaviour within the ISR range needs to be extensively explored. This paper might be useful to understand phenomena involving a dynamic process such as mechanical excavation in which rock experiences a loading lower than high strain rate, i.e., explosive blasting, and higher than static loading. [ABSTRACT FROM AUTHOR]