Study on Influence of Shallow Buried Tunnel Excavation on Adjacent Bridge Piles

The influence of metro tunnel excavation on the surrounding existing structures should not be ignored. According to the characteristics of the tunnel side passing through the Beiyuan viaduct pile of Jinan Metro Line R2, the construction process is simulated by using FLAC3D software. The influence of tunnel excavation on adjacent bridge piles is studied. The results show that during the construction of double track tunnel, the farther away from the tunnel axis, the smaller the disturbance caused by the construction. Due to the disturbance of the stratum caused by the construction of the large excavation section of the left line tunnel, the maximum settlement value of the surface is directly above the axis of the left line tunnel. The vertical deformation curve of the stratum presents an asymmetric double concave groove distribution. By adopting the advanced support scheme of WSS deep hole grouting + advanced small catheter, the pile deformation and the uneven settlement of the ground surface is effectively limited. The longer the length of the pile embedded in the rock mass, the smaller the horizontal displacement generated by the pile bottom. The research can provide reference for the construction of similar tunnel side crossing bridge piles in the future.