## 7 Conclusions  
Relyin1g on the newly built Shimentangshan tunnel, this paper analyzes the deformation rules, the reasonable construction sequence, and the drift ratio of a shallow unsymmetrical loading section of a super-large-span tunnel based on a field test and numerical simulation, and puts forward stability control measures. The conclusions are drawn as follows:  
1. The arch settlement and horizontal convergence of the monitoring section mainly experience three stages: rapid growth, slow deformation, and stabilization. The deformation lasts a long time and finally reaches a relatively stable state. The deformation of each part is less than the reserved deformation; the tunnel deformation is the largest on the left, followed by the smallest on the right; and temporary support has a great impact on the initial support structure. The removal of the temporary support makes the deformation of the initial support quickly enter into a stable state, which mainly affects the resharing of the vertical load.
2. With the shallow-side-first excavation scheme, the arch settlement and plastic zone of the surrounding rock are smaller than the deep-side-first excavation scheme, while the horizontal convergence has no obvious difference, so the shallow-side-first excavation scheme is slightly better than the deep-side-first excavation scheme; with the increase in the ratio of drifts, the arch settlement of the various drifts and the horizontal convergence show a tendency to increase, and the scope of the plastic zone also gradually increases, with the initial support structure stress exhibiting a pattern of decreasing followed by an increase as the drift ratio increases. The structure reaches its most stable stress state at around 0.3.
3. According to the field test results of tunnel deformation and the numerical simulation results of the construction scheme, control measures such as strengthening the advance support, improving the stiffness of the initial support, adopting bolt and grouting of surrounding rock, controlling the length of the benches, and optimizing the construction sequence and the proportion of the drifts on both sides are proposed.
4. The scope of this study is focused on construction optimization, but it is important to note that when dealing with shallow buried unsymmetrical strata, design parameters like flatness and unsymmetrical degree of super-large-span tunnels play a significant role in structural stability. Future research should consider delving deeper into tunnel section and support structure design.  
Conceptualization, L.W. and C.T.; Methodology, Y.L.; Validation, C.Z. and X.S.; Formal analysis, C.T.; Investigation, C.T.; Resources, Y.L.; Data curation, Z.L.; Supervision, L.W. and Y.L. All authors have read and agreed to the published version of the manuscript.  
The authors would like to acknowledge the financial support provided by the National Natural Science Foundation of China (grant no. 5197081888), the Science Fund for Distinguished Young Scholars in Shaanxi Province (grant no. 2020 JC-28), the Collaborative Research Project with Shandong Provincial Communications Planning and Design Institute Group CO., LTD. (grant no. 2020-KJ-046).  
Not applicable.  
The data presented in this study are available upon request from the corresponding author. The data are not publicly available due to privacy.  
The authors are grateful for the comments provided by the anonymous reviewers.  
Authors [PERSON], [PERSON], and [PERSON] were employed by the company Shandong Provincial Communications Planning and Design Institute Group CO., LTD. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.