Performance analysis of drilling machines based on rock properties and machine's specifications

Performance analysis of drilling machines and estimating drillability of rock is a critical process for every drilling operation, since estimating the drillability by means of the rate of drilling (DR) has a significant impact on the cost and time scheduling of rock excavation projects. The aim of this study is to estimate the DR of both diamond and percussive drilling machines using rock properties and drilling machine specifications. For this aim, the datasets related to two different drilling methods were developed by collecting raw datasets from available project reports and literature. Each established dataset consists of two parts: rock properties including uniaxial compressive strength, Brazilian tensile strength, density, and brittleness, and specifications of diamond and percussive drillings including thrust, rotational speed, bit diameter, and operational pressure respectively. After establishing these datasets of two drilling methods, regression analyses composed of simple, multiple linear, and non-linear regressions were conducted to develop the best model for the prediction of DR for each drilling method. It is found that non-linear multiple regression analysis should be used to develop highly accurate models, since the estimation of DR is a complex and non-linear problem to be solved with multiple variable regression analysis. Concluding remarks is that even though developed models have some limitation due to the range of data in the datasets, the DR of both diamond and percussive drilling can be estimated using the non-linear multiple regression equations with correlation coefficients of 0.87 and 0.85 respectively as a function of measured rock properties and drilling machine's specifications.