Analysis and discussion on Brazilian tests on layered rock tensile strength

In order to analyze the applicability of Brazilian disc splitting method in tensile strength test of layered rock mass, by analyzing Brazilian splitting test results of the layered rock mass, selecting the bedded sandstone as test subjects, a kind of Brazilian disc split test considering sandstones' different bedding angles has been designed and then carried out. The results show that:(1) The anisotropy of the tensile strength of layered rock is very obvious; and the influence of bedding angle on the splitting tensile strength of layered rock mass is substantially similar, but the degree of influence is different. (2) The difference of different bedding angle disc samples' fracture surface shape is large; the failure modes can be summarized as linear, bent and arc. (3) When the bedding angle is in the range of 0 degrees < beta < 90 degrees, the development law of rupture surface can not strictly meet the assume of Brazilian splitting test disc mechanics model; the splitting tensile strength calculated by the equation (1) can only be an approximate value. (4) When the rock sample materials and bedding structure are symmetry distributed on both sides of the disc samples` load line, the stress distribution in the disk during the loading process can better satisfy its theoretical calculation model; the test results are more accurate. The research results can provide a good reference for the tensile strength's accurate determination of the layered rock.