Experimental Study Of Mechanical Properties Of The Deep Fine Sandstone Under Impact Loading

Due to the complex stress state of deep rock mass, moreover, deep rock is subjected to impact loading. Thus the mechanical properties of deep rock and shallow rock have significant differences. Hereby, it is a necessity to study the mechanical properties of deep rocks under impact loading. Uniaxial compression and tensile tests were performed by using Universal material testing machine and Split Hopkinson Pressure Bar(SHPB) device, the mechanical properties of rock were studied under different strain rates, water content and temperature. Furthermore, the deformation and failure of the sample was recorded by High-speed cameras, DIC method studied the strain distribution; a typical experiment SHPB model was simulated to reappear the deformation and failure process by using ANSYS/LS-DYNA.Under normal temperature, the compressive and tensile strength of deep fine sandstone increased according to the growth of strain rate, and then growth amplification slowed down when the strain rate increases to a certain extent. The influence of strain rate was significant for failure mode, but not so remarkable for failure strain. Based on the same strain rate and normal temperature, the compressive and tensile strength of natural sample was greater than saturated sample, water content was not that important for failure mode. And the failure strain of saturated sample was slightly larger than natural sample in dynamic tensile test. When it came to a same strain rate, the compressive strength of deep fine sandstone dropped while the temperature growed; however, the tensile strength of deep fine sandstone was increased according to the growth of temperature. The influence of temperature was not significant for failure mode. In the crack propagation process of dynamic test, the influence of strain rate and water content was different at different state.