The stress of soft and hard interbedded mass is complex. Therefore, pre-fabricated specimens of interbedded surrounding rock tunnel in different thickness ratio of soft and hard interbedded mass were prefabricated to study the deformation and failure characteristics around the interbedded rock tunnel through experiments. The stress and strain distribution around the interbedded rock tunnel were analyzed and compared by numerical simulation. The results show that: When the relatively soft layer is thick, the damage of the tunnel is more affected by the compression of the relatively soft layer, and the axial compression deformation of the tunnel is larger. When the relatively hard layer is thick, the damage of the tunnel is more affected by the fracture of the relatively hard layer. When the interlayer thickness is thin, the thinner rock layer makes the deformation and failure of rock mass around the tunnel more continuous. (1) The overall failure mode of the test specimen under the condition of 10 mm relatively hard layer and 10 mm relatively soft layer is strong hole failure mode, in which the tensile failure is more serious at the vault and arch bottom, and pressure-shear composite crack is easily occurs at the arch shoulder and arch foot. (2) The overall failure mode of the test specimen under the condition of 10 mm relatively hard layer and 20 mm relatively soft layer is strong compression failure mode, in which the compression-shear failure is obvious at the arch waist, and the compression-shear composite crack is easily occurs at the arch shoulder and arch foot. (3) The overall failure mode of the test specimen under the condition of 20 mm relatively hard layer and 10mm relatively soft layer is fracture failure mode, in which the vault obviously sinks, and the stress level near the arch waist is high, but the failure degree of the arch waist is small.

The dilatancy test of concrete samples with non-circular holes was carried out by using a self-designed splitter. The failure load characteristics, crack propagation law and stress distribution around the holes of specimens with different hole shapes were studied. The results show that: compared with the circular hole specimens, the peak load of the elliptical hole, rectangular hole and diamond hole specimens is significantly reduced, and the load reduction ratio is 28.2% ~ 70.3%. Elliptic, rectangular and rhomboid holes all have a guiding effect on the crack initiation. The guiding effect of elliptic and rhomboid holes on the crack initiation increases with the increase of the ratio of the long and short axes (diagonal lines), while the guiding effect of rectangular holes does not change significantly with the change of the ratio of the side length. In terms of crack guiding effect, rhomboid holes are better than elliptic holes, and elliptic holes are better than rectangular holes. The change in the shape of the cavity produces the obvious tensile stress concentration phenomenon, and the degree of tensile stress concentration at the long axis of the elliptical cavity increases with the increase of the ratio of the short axis to the long axis. The degree of tensile stress concentration at the four tips of the rectangular hole decreases first and then increases with the increase of the ratio of side length. The tensile stress concentration of rhombic hole increases first and then decreases with the increase of diagonal ratio.