## 1 Introduction  
Urban subway networks are expanding, leading to the emergence of rail transit hubs that interconnect various lines. Hub stations, with their complex layouts and multiple intersections, significantly influence nearby tunnels during deep excavation activities. Excavation of the foundation pit disrupts the equilibrium of the surrounding soil, causing deformation and displacement, particularly in tunnels parallel to the pit. Significant tunnel deformation can result in cracks and leaks, thereby jeopardizing rail transit safety; therefore, precise analysis and control of the impact of hub construction on adjacent tunnels are crucial. In the field of underground structures and geochemical engineering, the influence of foundation pit excavation on surrounding tunnels has long captivated researchers. Scholars globally have explored this issue from various angles, including theoretical analysis [1; 2], numerical simulation [3; 4; 5], physical model experiments [6; 7], and field monitoring [8; 9; 10]. [PERSON] and [PERSON] [11; 12] proposed a sidewall unloading model that considers the deformation of retaining structures during excavation, providing essential theoretical support and validating the reliability of their approach. [PERSON] [13] offered specific recommendations for optimizing excavation methods through numerical simulations of the divided alternate excavation method, advancing engineering practices. [PERSON] [14] analyzed extensive monitoring data and proposed empirical equations to predict the deformation of existing tunnels, providing valuable insights regarding risk assessment and control in practical engineering. [PERSON] [15] investigated the effects of large excavations in soft soils on existing metro tunnels and proposed effective protective measures, offering practical recommendations for underground engineering safety. [PERSON] and [PERSON] [16; 17] conducted thorough studies on the stability of tunnels under excavation through numerical simulations and finite element analyses, suggesting corresponding safety evaluations and protective measures. [PERSON] and [PERSON] [18; 19] examined the effects of different support schemes on nearby tunnel deformations through numerical simulations and theoretical calculations, providing technical guidance for engineering practices. [PERSON] and [PERSON] [5; 20] derived regression equations and conducted impact factor analyses to predict tunnel deformations through geological monitoring and finite element modeling, providing important reference points for engineering design and construction. [PERSON] and [PERSON] [21; 22] conducted laboratory experiments and numerical simulations, respectively, illustrating the effectiveness of a grouting layer in enhancing the lining resistance to deformation, particularly when tunnels pass through settlement-sensitive zones. Previous research has established a solid foundation for understanding how foundation pit construction impacts tunnel deformation; however, it is crucial to acknowledge the regional and uncertain nature of foundation pit engineering. The impact of different support systems on nearby buildings and structures varies, especially for lateral tunnels close to the site. This paper aims to compare and analyze field monitoring data and numerical simulation results from a hub foundation pit project in Shenzhen, seeking to explore how adjacent lateral foundation pit excavation affects existing tunnels in the project area while analyzing the sensitivity of retaining structure parameters and providing a basis for understanding the impact of foundation pit excavation.