Selection and mechanical properties testy of similar brittle rock-like model materials of basalt

The occurrence environment of special discontinuous columnar jointed basalt in the engineering excavation area often has complex geological conditions and high in-situ stress levels. The basalt block has high uniaxial compressive strength and strong discreteness. Its brittle tensile splitting failure characteristics are obvious. The primary hidden fracture has obvious influences on the strength and deformation of the basalt block. Taking the hard and brittle basalt as the research object, by preparing the model material samples with 5 types of mass ratios, based on the uniaxial compression tests, Brazilian splitting tests and acoustic emission tests and other technical means, and on the principle of similarity ratio, the brittle rock-like model materials that can be used to simulate the mechanical response of columnar jointed basalt blocks are selected in terms of the form of stress-strain curve, failure mode of samples, compression-tensile ratio (brittleness index) and physical and mechanical parameters. The research results can provide technical and material supports for the researches on the physical model test on the anisotropic mechanical response, damage evolution characteristics and seepage-stress coupling characteristics of discontinuous columnar jointed basalt.