## 5 Conclusions  
We used PLAXIS 3D finite element software to study the impact of super large-diameter shield tunnel excavation on existing bridge piles. Combined with the construction monitoring data, the following conclusions are drawn:  
1. [label=(0)]
2. Sleeve valve pipe pre-grouting reinforcement between shield tunnel and bridge pile foundation. After shield tunnelling to strengthen the stratum, the maximum simulated surface settlement was 19.4 mm, and the influence range of the settlement groove was about 60 m. According to the field data of shield tunnelling monitoring points, the surface settlement of the pre reinforced stratum around the bridge pile was about 25 mm, which is slightly larger than the simulation value but meets the requirements of surface settlement control. The maximum surface settlement was 35 mm at the position of the unreinforced stratum near the bridge pile, indicating that the stratum reinforcement significantly reduced the impact of shield construction on the soil. 3. After the super large diameter shield tunnel passed through the reinforced stratum, the vertical displacement of the pile decreased with the deepening of the pile body. The maximum vertical displacement of the simulated bridge pile was 3.0 mm at the pile top and 0.7 mm at 5-6 m of the pile body, and the stress of the bridge pile met the strength requirements. During the construction, settlement monitoring points were set on the bridge pile. During shield crossing, the final settlement of the bridge pile was stable to 1.48 mm after a small settlement before crossing, and floated for a short time, which is less than the numerical simulation analysis value, indicating that the grouting reinforcement between the tunnel and the pile foundation had a noticeable control effect on the pile displacement and achieved a good reinforcement effect. 4. Through the pre reinforcement of Shield Crossing front sleeve valve pipe, the surface and bridge pile displacement met the deformation control standard, and the risk of  
Figure 14: Vertical displacement of the tunnel vault. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Top Pressure of** & **Total Thrust** & **Advance Rate** & **Cutter Head** & **Cutter Head** \\
**Slurry Silo (Bar)** & **(kN)** & **(mm/min)** & **Speed (rad/min)** & **Torque (kN\(\cdot\)m)** \\ \hline
1.18\(-\)1.12 & 52,920\(-\)62,600 & 6\(-\)13 & 1.2 & 11,200\(-\)16,110 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: The shield tunnelling parameters. short-distance crossing bridge pile was generally controllable. If it is necessary to set reasonable tunnelling parameters before crossing, to strictly control the tunnelling attitude of the shield, pay attention to control the tunnel face pressure, adjust the slurry pressure in a timely manner, reduce disturbance to the soil, and achieve continuous, balanced and stable advancement. * The successful crossing of the Hongling Interchange No. 1 bridge provides a theoretical basis and engineering practice for the 16 m super-large diameter shield to cross an existing bridge pile foundation in a short distance in composite stratum with uneven, soft and hard features. This has significance reference value for similar projects. Conceptualization, J.W. and J.Z. ; methodology, Z.T. ; software, X.W. ; validation, X.L., M.L. and Z.T. ; formal analysis, J.Z. ; investigation, J.W. ; data curation, J.W. ; writing--original draft preparation, J.Z. ; writing--review and editing, J.W. ; visualization, X.W. ; supervision, M.L. ; project administration, X.L. All authors have read and agreed to the published version of the manuscript. This research received no external funding. The participant's personal identification information used in the study did not include personal information. Ethical review and approval were not required for the study. Data Availability Statement: Data sharing is not applicable. The authors would like to thank the anonymous reviewers for their valuable comments that helped improve the paper's quality.