## 6 Conclusions  
This paper uses the first four-lane super large section highway tunnel in Jiangxi Province as a case study and employs ABAQUS finite element software to simulate and compare the effects of three excavation methods on tunnel excavation. The patterns of surrounding rock stress, rock displacement, and initial lining stress are explored, and the conclusions are as follows:  
1. When adopting the three-benching seven-step method, the stress (maximum principal stress value reaches 0.621 MPa) released by the surrounding rock support is larger than that of the other two methods and is prone to stress concentration. Therefore, the initial support should be completed in time and the tunnel portal should be closed as soon as possible during the construction process to reduce the possibility of collapse. 2. Analysis of the surrounding rock and initial support stress indicates that the maximum principal stress generated during the excavation process occurs at the arch foot in all three methods. Strengthening stability support at the arch foot of the tunnel during construction is of significant importance. 3. The construction of large section tunnels involves complicated steps, multiple sequences, and extended durations. In actual construction, the stress in the surrounding rock is generally released before the completion of the secondary lining support, with the primary lining becoming the main support to bear the stress. It is essential to focus on reinforcing the primary support to ensure construction safety. 4. During the construction process using the CRD method, the disturbance to the surrounding rock is more significant, while the double-side drift method causes less disturbance to the surrounding rock. Compared to the CRD method and the three-benching seven-step method, the tunnel vault's settlement value caused by the double-side drift method is reduced by 14% and 19%, respectively, making it more suitable for constructing large section tunnels. 5. Based on the numerical results and the monitoring data, it is suggested that the double-side drift excavation method be preferred for similar large section tunnels (particularly tunnels with a surrounding rock grade of III to V), as it is beneficial for ensuring the safety of tunnel construction and providing economic savings. Conceptualization, Y.S. ; software, L.D. ; validation, L.D. ; investigation, J.H. ; data curation, Y.S. ; writing--original draft preparation, S.X. ; writing--review and editing, Y.R. ; visualization, F.Z. ; supervision, C.X. ; project administration, W.H. ; funding acquisition, C.X. and Y.R. All authors have read and agreed to the published version of the manuscript. Figure 13: Diagram of model validation. (**a**) Settlement of tunnel arch top; (**b**) settlement of surface [45; 46]. **Funding:** This research was supported by the National Key R&D Program of China, grant number 2023 YFC3009400; the National Natural Science Foundation of China, grant number 52238009; the Science and technology project of Jiangxi Provincial Transportation Department, grant number 2023C0001, Ganpo Juncai Support Program-Training Program for Academic and Technical Leaders in Major Disciplines-Young Talents (Technical Category), grant number 20232 BCJ23069. **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author. **Acknowledgments:** The authors acknowledge the financial support provided by the National Natural Science Foundation of China and the Jiangxi Provincial Transportation Department. **Conflicts of Interest:** Authors [PERSON] and [PERSON] were employed by the company Jiangxi Transportation Research Institute Co., Ltd. Author [PERSON] was employed by the company Jiangxi Provincial Communications Investment Group Co., Ltd. Author [PERSON] was employed by the company Zhejiang Jiaogong Group Co., Ltd.