Abstract: After the excavation of the bias tunnel through the fracture zone,the deformation and support force of the surrounding rock is large,causing asymmetry between the deep and shallow buried sides. This resulted in concrete spalling and steel frame distortion on one side of the tunnel. We analyzed the variation and distribution of the deformation and surrounding rock pressure based on field test data. Combined with numerical simulation,we optimized the tunnel excavation sequence and the layout of long and short rock bolts. Based on the double-layer advanced small catheter,we proposed targeted measures of excavating the deep buried side first with three benching and seven steps,asymmetric arrangement of rock bolts,and radial grouting. These measures were verified for feasibility through field experiments. The results show that there is obvious asymmetry in deformation and surrounding rock pressure on both sides of the tunnel,and the deformation lacks a convergence stage,indicating that the original design scheme could not provide sufficient support force. After implementing the targeted measures,the average crown settlement reduced by 40.4%,the average horizontal convergence reduced by 54.0%,and the tunnel deformation was better controlled. The surrounding rock pressure on the left arch shoulder and left arch foot reduced by 25.4% and 29.7% respectively. The convergence ratio of the left and right arch waist reduced from 1.60 to 1.12,and the surrounding rock pressure ratio of the left and right arch foot reduced from 2.13 to 1.46 times,resulting in a reduction of asymmetry in deformation and force. The occurrence of large deformation disasters reduced,and the construction efficiency significantly improved. These results provide references for the construction and design of similar bias tunnels.