Experimental Studies of the Influence of Dynamic Loading on the Elastic Properties of Sandstone

Under dynamic loading, the geomechanical properties of porous clastic rocks differ from those in quasistatic loading. A small experimental rig was built to directly assess the influence of vibrations on the uniaxial compressive strength (UCS), Young modulus, and Poisson's ratio. A piezoelectric actuator powered by a signal from an oscillator was used in the rig as a generator of vibrations. A laser sensor and eddy current probe measured the longitudinal and transverse deformation. Tinius Hounsfield and Instron Series 4483 installations were used to determine the geomechanical properties of new red sandstone in a quasistatic regime. The boundaries of elastic deformations determined in the quasistatic loading were implemented in the dynamic loading. To perform the experiments in the elastic zone (on the graph of stress (sigma)-strain (epsilon)), small samples with diameters ranging between 7.5 and 24.7 mm were manufactured. The investigation demonstrated that the Young's modulus of the sandstone increased with increasing values of the dynamic load and frequency.