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چکیده
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In this research, the relationship of vertical drilling rate (VDR) with rock properties was studied in the marble quarry mining based on the combination of field surveys and laboratory experiments. To achieve this, the VDR was initially measured while drilling at the Malawi marble quarry mine. Then, the physical and mechanics tests were conducted on the core specimens prepared from the collected minor blocks corresponding to the under-drilling mine benches. The parametric study revealed that natural density, dry density, slake durability index, Schmidt hammer rebound, compression wave velocity, point load index, uniaxial compressive strength and modulus of elasticity exhibit an inverse relationship with VDR. Conversely, VDR was found to have a direct relationship with porosity, water content, Los Angeles abrasion, and Poisson's ratio. Moreover, it was confirmed that the VDR is more correlated with the rock mechanical properties rather than the rock physical features, considering the obtained mean coefficient of determination (COD) values of 0.8948 and 0.9206, respectively. Besides, sensitivity analysis showed that modulus of elasticity and water content are the most and least effective variables on VDR with influence values of 1.152 and 0.8865, respectively. Additionally, statistical analyses were conducted and optimum empirical quadratic, power, and exponential relationships with high accuracy (COD values from 0.861 to 0.987) were proposed to determine the VDR based on each rock property. Finally, comparative analysis was conducted for further verification of the current study. Accordingly, the values of lower and upper limits of COD, and mean relative error were obtained 0.36, 0.9576, and 0.359 for previous researches, compared to 0.861, 0.987, and 0.114% for this study. These results confirmed the superiority of the current research compared to similar previous studies.
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