灰绿色砂岩三轴压缩试验及声波特性研究

his paper presents the results of triaxial compression strength and acoustic properties of greyish green sandstone in Taiyueshan tunnel at different confining pressures by using RMT-301 rock mechanics test system and GCTS ULT-100 ultrasonic measuring system. The results show that: (1)The peak and residual strength are gradually improved with the increase of confining pressure. Although the stress-strain curve fluctuate jagged, the results of peak and residual strength are proportional to the applied confining pressure. (2)The failure mode under 2, 4 and 6 MPa confining pressure following the Mohr-Coulomb failure criterion, the fracture angle after the destruction is close to the calculated angle by Mohr-Coulomb failure criterion, the actual fracture angle can be predicted on the basis of the failure criterion. (3)The variation of P wave velocity is basically the same as the variation of stress-strain curve at corresponding confining pressure during the experiment process, however, P wave velocity varied irregularly with the increase of confining pressure duo to the presence of micro-cracks and pores.