<p>Shield tunnels are constructed by assembling precast segments with bolts, resulting in relatively weak longitudinal load-bearing capacity. Consequently, under surface loading, operational shield tunnels are prone to longitudinal differential settlement, which can induce structural distress and adversely affect normal operation. This manuscript first examines the patterns of longitudinal differential settlement in shield tunnels under surface loading through engineering case studies, analyzing the deformation and failure characteristics of the tunnel segment structure. Subsequently, detailed similitude model tests were conducted, fully accounting for joint effects, to investigate the influence of factors such as tunnel burial depth, soil properties, and surface loading on the differential settlement of operational shield tunnels. Finally, based on the test results, the longitudinal deformation behavior and earth pressure distribution characteristics of shield tunnels under various influencing factors were analyzed. The findings indicate that: The greater the tunnel burial depth, the more pronounced the soil arching effect, when the burial depth exceeds 3D, the influence of local loading on longitudinal settlement is minimized. The magnitude of longitudinal differential settlement decreases as the load offset distance increases; when the offset distance is less than 2D, the impact of local loading on the shield tunnel becomes significant. Compared to longitudinally uniform soil layers, when the tunnel traverses a soft soil interlayer, its maximum settlement increases sharply; moreover, the lower the compression modulus of the soft soil layer, the greater the settlement. The research outcomes aim to provide valuable references for the design and operational management of shield tunnels.</p>