Uniaxial tensile failure properties of rock-like specimens with two overlapped X-type flaws

Although the failure properties of rock / rock-like specimens with flaws under uniaxial compression have been studied in many cases,those properties of specimens with X-type flaws under uniaxial tension have not been researched yet. In this research the crack coalescence and strength properties were studied with rock-like material specimens con- taining two overlapped X-type flaws under uniaxial tension tests. The testing results were compared with uniaxial com- pression results of specimens containing corresponding flaws. The study results show that the failure and coalescence modes of specimens with two overlapped X-type flaws under uniaxial tension tests are different from those with speci- mens under uniaxial compression tests. There is no crack coalescence at the rock bridge areas of specimens containing two overlapped X-type flaws under uniaxial tension tests. The position of the secondary flaw influences the strength of specimens containing two overlapped X-type flaws under uniaxial tension tests. The specimen with a second flaw verti- cal to the maximum tension stress has the lowest tension strength among specimens with two overlapped X-type flaws under uniaxial tension tests. The tension strength of the specimen with a second flaw parallel to the maximum tension stress is the highest one among the specimens with two overlapped X-type flaws under uniaxial tension tests.