LAUSR

Abstract Natural coal used in experiments often contains unknown substances which endow it with strong anisotropy and affect the accuracy of experimental results. This paper is aimed at analyzing the single-factor and two-factor-coupling influences on the properties of coal-like materials with different proportions. A coal rock drillability evaluation system was developed based on the principle of Frechet distance algorithm to evaluate the similarity between drilling simulation experiment data of coal-like materials and natural coal. The results disclose that the cement is of the most notable regulating effect on the material properties. Under the coarse-to-fine ratio of 1:4, the cement content of 20%, the molding pressure of 25 MPa and the pressure holding time of 0.5 h, the coal-like materials are of the optimal mechanical and gas adsorption properties. The fluctuation characteristics of drilling experimental data curve are the most similar to those of natural coal, with the similarity ratio being 0.54.