<p>Shield tunneling through fractured zones can cause uneven settlement, leading to segment ring gap openings, misalignment, and leakage, which threatens both structural stability and operational safety. To investigate the impact of these effects, this study establishes four normalized load distribution models for the overlying soil, based on the loosening soil pressure theory. A random field model for the elastic modulus, a key geotechnical parameter of the fractured zone, is constructed using the Karhunen-Loève expansion method, representing its longitudinal spatial variability. By modifying Timoshenko beam theory on a Winkler foundation and incorporating the longitudinal variation of the foundation reaction coefficient, this study couples the random field with the modified beam model, solving it using the finite difference method. An analytical approach for the longitudinal mechanical response of shield tunnels in fractured zones is then proposed. The results are as follows: changes in the dip angle, burial depth, and width of the fractured zone significantly alter the overburden load distribution, with the largest forces occurring in the Type 3 load configuration. When the burial depth is less than three times the tunnel diameter, the forces on the shield tunnel are more sensitive to depth variations. When the depth exceeds three times the diameter, however, the forces are primarily influenced by the load configuration. The stochastic field analysis shows that the mechanical responses of the tunnel are most pronounced at the center of the fractured zone. Although the response quantities approximate a normal distribution and the deterministic values are close to the mean of the distribution, the extreme values still indicate potential engineering risks. The findings provide an important theoretical basis for risk assessment and the development of preventive measures for shield tunnel projects in fractured zones.</p>