Study on Brazilian Splitting Mechanics and Acoustic Emission Characteristics of Impure Salt Rocks

Abstract In order to study the mechanical and acoustic emission characteristics of salt rock under indirect tension, we conducted indirect tension cyclic loading and unloading tests and acoustic emission monitoring on pure salt rock and impure salt rock respectively by using MTS815 Flex Test GT rock mechanics test system and PCI-II acoustic emission (AE) three-dimensional positioning system. The results show that: (1) Both salt rocks show strong plastic deformation characteristics, but the plastic deformation ability of salt rocks is weakened by impurities, which is 79% of the average deformation ability of pure salt rocks. (2) The peak load and tensile strength of impure salt rock are higher than those of pure salt rock. The average peak value is 11.18KN and the average tensile strength is 1.81MPa, which are 1.55 times and 1.60 times of pure salt rock respectively. (3) The indirect tensile deformation characteristics of salt rock can be divided into three stages: damage stage at contact site, tensile deformation stage and post-peak deformation stage. (4) The acoustic emission signal is the most intense near the peak value, but the maximum ring counting rate and energy rate of impure salt rock are higher than those of pure salt rock. (5) When salt rock is destroyed, the whole crack surface is destroyed by tension, but the crack area of pure salt rock is much larger than that of impure salt rock.