Study on uniaxial compression mechanical properties of sandstone with different moisture content and wave velocity method

In order to investigate the mechanical properties and damage of sandstone under different uniaxial compression, the static uniaxial compression tests of five sandstones with different moisture content were carried out, and the physical and mechanical parameters were obtained. And the wave velocity of the sandstone samples with different moisture content were measured by ultrasonic detector. Then the sandstone was loaded to 80% peak intensity and then unloaded to 0. The acoustic wave velocity of sandstone was measured at this time. The damage was determined by acoustic wave method. The results show that the peak strength of sandstone under uniaxial compression and the elastic modulus decreases with the increase of moisture content, but the peak strain changes in the opposite direction; the total work and elastic energy decrease with the increase of moisture content, and the dissipation energy change is opposite with the moisture content. The effect of sandstone damage indicates that the wave velocity of the acoustic wave decreases with the increase of moisture content before the test. The wave velocity of the acoustic wave decreases with the increase of moisture content and the trend is slower than that before the test. The residual plastic deformation of sandstone increases gradually with the moisture content; The internal damage of sandstone increases with the increase of moisture content. The results of the study can provide a basis for on-site testing of rock damage.