###### Abstract  
Due to the complexity of construction sequence and the extended duration required to construct super large section tunnels, the selection of excavation method critically influences the stability of the surrounding rock and support structures. In this work, the Xiaoyuan Tunnel project in Jiangxi Province serves as the research background for employing ABAQUS software to simulate the variations in displacement and stress within the rock and support structures under three different excavation methods. The simulated results are subsequently compared and verified against monitoring data. The findings indicate that the three-benching seven-step method releases more stress (maximum principal stress value reaches 0.621 MPa) from the surrounding rock and support structures than the other methods, resulting in stress concentrations. Therefore, it is of vital significance to complete the initial support in time and seal the tunnel opening quickly. The maximum principal stress values caused by three excavation methods all appear at the arch foot position, highlighting the need for prompt reinforcement of stability support there. 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. Furthermore, the largest disturbance of the surrounding rock occurs under the CRD method, while the double-side drift method minimizes such disturbances, making it the preferred choice for the construction of super large section tunnels. These insights are invaluable for guiding the selection and optimization of construction methods for such tunnels. superc large section tunnel; stress and deformation; excavation methods; numerical simulation; field monitoring +
Footnote †: journal: [PERSON]  
et al. [17] identified factors closely linked to the convergence of tunnel deformation, based on monitoring data. [PERSON] et al. [18] introduced the concept of stress distribution using the center-diaphrag method and determined the optimal distance between the excavation face and the excavation sequence. [PERSON] [19] developed a closed-form solution for the stresses and displacements around a tunnel using complex variable theory and the conformal mapping method. It is well established that stress redistribution occurs in tunnel sections at the initial stage of excavation, and stress concentration happens at the end of excavation. Thus, the stability of the rock surrounding the tunnel and the supporting structures can be effectively assessed by monitoring the change in surrounding rock stress at the tunnel opening [20; 21; 22; 23; 24]. He [25] achieved the digitization and automated analysis of structural surface information of tunnel rock bodies using image processing and structural feature extraction techniques. [PERSON] et al. [26] comparatively analyzed the model tests and numerical simulations, discovering that the surrounding rock damage zone gradually expands with increased burial depth. [PERSON] [27] extensively discussed the stability of large-depth cavern complexes using loading tests on tunnel rock hexahedra under three-dimensional stress states. [PERSON] [28] introduced various physical models suitable for tunnels in regions with soft soil geological conditions. [PERSON] [29] explored the deformation and damage mechanism of peripheral rock in a super large section of a tunnel with a small clear distance, noting that high-strength support can effectively control peripheral rock deformation. Using finite element simulations, [PERSON] et al. [30] observed that the displacement release coefficient during tunnel excavation is influenced by the excavation method and other factors. [PERSON] et al. [31] employed nonlinear analysis to identify the optimal excavation methods for large-span tunnels with varying levels of surrounding rocks. [PERSON] et al. [32] demonstrated that the mechanical behavior during tunnel excavation could be managed through active control technology, supported by on-site monitoring.