## 1 Introduction  
In recent years, the double-sidewall guide pit method has emerged as a crucial construction approach for mitigating disturbances to adjacent structures and tunnel deformations. This method addresses challenges posed by the dense urban population, extensive surface buildings, and the substantial infrastructure of subway pipe foundations and lines. Compared with other tunnel excavation methods, the double-sidewall guide pit method has great advantages in controlling surface settlement and horizontal displacement and is suitable for the construction of large cross-section tunnels [1; 2; 3]. Different excavation sequences of guide pits will have different effects on surface settlement, surrounding rock stresses, and lining stresses.  
There are many factors affecting the construction of the double-sidewall-guide pit method. In terms of theory, [PERSON] et al. [4; 5; 6] studied the effect of the double-sidewall-guide pit method on surface settlement, vault settlement, and horizontal deformation and concluded that the tensile stress is dominant in the connection part of the initial support and diaphragm wall and the compressive stress is dominant in the middle and lower parts of the support structure. [PERSON] et al. [7] studied the mechanical response of the support structure in the construction of a double-sidewall-guide pit in Class V enclosing rock. [PERSON] et al. [8; 9; 10] conducted on-site monitoring and analysis of the large cross-sectiondouble-sidewall tunnels using the double-sidewall guide pit method and concluded that the deformation and force of the surrounding rock and lining are mainly directly related to the construction process and geological conditions used. [PERSON] et al. [11; 12] explored how the mechanical behavior of the surrounding rock palm surface changed with the construction sequence and determined and elucidated the influence of the construction sequence on the surface displacement caused by a tunnel excavation. [PERSON] et al. [13; 14; 15; 16] optimized the excavation sequence of the cross-section of tunnels using the double-sidewall guide pit method according to an actual situation on site, and the study showed that the support structure induced by the excavation sequence after the optimization was very good. [PERSON] et al. [17; 18] optimized the core column width of tunnels using the double-sidewall guide pit method, and the analysis showed that there was an optimal value for the core column width that could improve the stability of the surrounding rock. [PERSON] and [PERSON] et al. [19; 20; 21; 22; 23; 24; 25] optimized construction parameters, compared the effects of different curvature radii and excavation schemes on the stability of surrounding rock, and selected the best construction scheme. [PERSON] et al. [26; 27; 28] optimized the construction sequence of the double-sidewall guide pit method, adapted the excavation form of the upper and lower sections, and preserved the core rock columns in the middle soil layer, which accelerated their construction progress and improved the overall stability of the tunnel.  
This paper, building upon prior research findings, undertakes a comparative analysis of surface settlement, surrounding rock stress, and lining stress resulting from diverse construction sequences. The investigation employs indoor model tests to elucidate the mechanical response characteristics of both the surrounding rock and supporting structure during tunnel excavation under various construction sequences.