Impact of Bedding Planes on Mechanical Properties of Sandstone

Laboratory compression tests were carried out on the interbedded sandstone under various confining pressures and loading angles as well as tension tests under various loading angles. The testing results revealed that the mechanical properties of the interbedded sandstone were significantly influenced by stress levels and structural anisotropy. The Young’s modulus of sandstone at a loading angle of θ = 0° was greater than that at θ = 90°, and both were apparently greater than that at θ = 30°. The variation rules of sandstone compressive strength with the change on loading angles were similar to those of the Young’s modulus, and all exhibited apparent brittle failure features. The axial strain corresponding to the peak compressive stress at θ = 90° was greater than that at θ = 0°, and the axial strain at θ = 30° was relatively small as the peak compressive strength was low. The tensile strength of sandstone increased with increasing the loading angle.