## 1 Introduction  
With the burgeoning development of urban areas and the continuous increase in population density, the daily commuting volume is gradually rising, leading to increasingly strained surface transportation. To alleviate surface traffic congestion, the expansion of underground transportation networks has become essential. As vital components of metropolitan infrastructures, subways and road tunnels play a crucial role in urban mobility [1]. The shield method, notable for its efficiency, cost-effectiveness, and minimal environmental impact, has emerged as the predominant construction technique for these structures [2]. However, the integration of new construction projects poses significant challenges to existing tunnels, such as the impact of ground surcharge and the unloading of excavation pits adjacent to construction loads. Under the influence of these new construction loads, the structural force balance of tunnels can be disrupted, leading to excessive convergence, joint opening, and cracking in lining structures [3; 4; 5; 6]. In major cities like Shanghai, ground surcharge impacts, primarily from new constructions or soil accumulation in foundation pits, have been identified as primary causes of operational disruptions. And these impacts often result in substantial deformation and joint openings in tunnels, threatening their operational viability [3; 7]. This study aims to address these challenges by investigating the effects of ground surcharge on tunnel structures, with a focus on deformation characteristics. The impact of ground surcharge on tunnel structures has been extensively explored in past research, with the use of diverse methods, such as theoretical calculations [3; 8; 9; 10; 11], full-scale [12; 13; 14] and scaled model tests [15; 16; 17], field measurements [18; 19], and, predominantly, numerical simulations. The preference for numerical simulations stems from their cost-effectiveness and capability to yield comprehensive data. This study seeks to advance this field by addressing the limitations of the existing approaches and enhancing the precision and applicability of simulation methodologies, particularly in the context of complex urban tunnel systems. This study establishes a three-dimensional refined analysis model of a shield tunnel lining structure with staggered joint assembly using finite simulation calculations, including precast concrete segments, rebar, and joint bolts. It also takes into account the interfacial friction between segments and the interaction between rings, and verifies the reliability of the numerical model based on the results of full-scale model tests. In recent studies, the stability and deformation of various tunnel types under ground surcharge have been extensively explored. [PERSON] et al. [20] used numerical simulation to study the evolution of the transverse deformation of shield tunnels under ground surcharge, established the relationship between the convergence of the tunnel and the concrete force, bolt force, and joint opening, and the proposed convergence of the tunnel as a judgement indicator for the development of the lateral structural state of tunnels. [PERSON] et al. [21] developed a 3D numerical model of a shallow shield tunnel in soft soil, assessing ground and tunnel deformations under various surcharge scenarios. The numerical simulations show that the surface and tunnel deformation responses vary when induced by different loading modes above shallow shield tunnels in soft soil. [PERSON] et al. [22] created two tunnel models in different permeability soils using Fast Lagrangian Analysis of Continua, focusing on surcharge effects in saturated foundations, and noted that the stability of tunnels in saturated foundations is mainly affected by the permeability of the lining and the long-term hydraulic response of the foundations. [PERSON] et al. [23] investigated the coupled effect of the soil spatial variations and the disturbance of ground surface on the existing tunnel using the random finite difference method.