Stability analysis of surrounding rock of bedding dolomite tunnel with different dip angles

Abstract To investigate the stability of surrounding rock of bedding dolomite tunnels with different dip angles, this study considers the diversity of tunnels in different geological conditions. In the case of five different bedding angles, the effects of different dolomite rock thicknesses, contact interlayer thicknesses, contact interlayer elastic moduli, contact interlayer cohesive forces, and contact interlayer friction angles on tunnel stability are analyzed. When the bedding angle is 22.5°, the surrounding rock displacement is the largest, the peeling between layers is obvious. The plastic zone of the surrounding rock is concentrated in the unsupported area of the tunnel. The contact interlayer has a weakening effect on the displacement of the surrounding rock and the expansion of the plastic zone. The thickness of the dolomite and the thickness of the contact interlayer have different effects on the displacement of surrounding rock of different bedding angles. Increasing the elastic modulus of the contact interlayer can reduce the displacement of the surrounding rock, increasing the internal friction angle of the contact interlayer has less influence on the displacement of the surrounding rock, and increasing the cohesive force of the contact interlayer can reduce the displacement of the surrounding rock.