Study on physical and dynamic splitting mechanical properties of temperature-water coupled sandstone

Abstract

Temperature and water are important factors to induce the mechanical properties of rock mass, the deformation and failure of rock under dynamic load such as blasting depends on its tensile strength. In order to study the influence of temperature and water coupling on the mechanical properties of rock dynamic splitting, the basic physical parameters of sandstone specimens were measured at room temperature and after 45 °C water bath treatment, and the dynamic splitting tensile tests at 8 loading rates were carried out using the Hopkinson pressure bar (SHPB) test apparatus. The results show that the mass and volume of sandstone specimen increased slightly after water bath, but the increase of density was small, and the increase of longitudinal wave velocity was obvious. The dynamic tensile strength and radial dynamic strain of the specimen have a quadratic function relationship with the loading rate, and the positive correlation is obvious, the dynamic tensile strength and radial dynamic strain show strong strain rate effect. The dynamic tensile strength of sandstone specimens after water bath is lower than that under natural condition, but the radial dynamic strain of the specimen after water bath is higher than its natural state. The strain rate increases as a power function of the loading rate, the strain rate of the specimen after water bath is higher than that under natural condition. The failure mode of the specimen after water bath satisfies the condition of validity of Brazilian disc.