used the advantages of numerical simulation in accuracy to establish a finite element model to study the deformation of adjacent tunnels caused by the excavation of pits supported by bored piles and inclined steel supports, and analyzed the effects of the geometric shape and the relative position of the tunnel and the pit on the lateral and vertical displacements of the adjacent tunnels. On this basis, they proposed a method for rapid prediction of maximum vertical displacements of the adjacent existing tunnels caused by the excavation of the pits. Based on this, a simplified analysis method is proposed to quickly predict the maximum vertical displacement of the neighboring existing tunnel caused by pit excavation. Considering the importance of shield tail grouting on surrounding structures and surface settlement and deformation, some scholars have explored grouting pressure [25; 26; 27]. [PERSON] et al. [28] used an equivalent circular domain, assuming that the grouting body is a uniform and equal-thickness elastic material, and considered the influence of the grouting body and the soil perturbation around the tunnel on the deformation of the ground surface. They investigated the influence of the working face support pressure and the shield tail grouting pressure on ground settlement in the construction of large-diameter shield tunnels and verified the accuracy of numerical predictions through field tests to determine the optimal construction parameters. In order to more accurately evaluate the quality of the shield tail grouting and analyze the deformation mechanism of the grouting layer under soil pressure during construction, [PERSON] et al. [29] designed a new experimental device to explore the influence of the characteristics of the grouting material on slurry deformation. They investigated the solidification mechanism of the slurry caused by different ratios of slurry and soil pressure. Based on the indoor test results, they optimized the numerical analysis, resulting in more accurate predictions of surface deformation. Through on-site monitoring combined with numerical simulation, [PERSON] [30] and [PERSON] [31] have analyzed the construction of new tunnels underneath existing tunnels and the construction of overlapping shield tunnels with small radius of curvature, and also studied the effect of reinforcement, based on actual engineering cases, which is of significance for similar current projects. Both domestic and international scholars have conducted extensive research and applications, but there has been no comprehensive exploration of the factors involved in tunnel deformation. Previous studies have primarily focused on the influence of a limited number of factors on tunnel structure deformation and stress. However, practical engineering considerations entail a myriad of factors. Utilizing data from a foundation pit excavation for a subway station adjacent to an existing tunnel, this paper's initial analysis focuses on monitoring data to determine variations in horizontal and vertical displacements of the tunnel, as well as differential settlement of structural joints during foundation pit construction. Subsequently, a two-dimensional numerical model of the foundation pit and tunnel is developed using ABAQUS software. The reasonableness of the model parameter setting is verified by comparing measured data with numerical simulation results. Lastly, exploration includes investigating the excavation depth of the foundation pit, horizontal spacing between the foundation pit and tunnel, stiffness of the supporting system (including size of supporting pile wall, insertion ratio, and horizontal support stiffness), and the impact of varying stratum conditions on tunnel structure stress and deformation.