To obtain mechanical properties of bell and spigot joint under precast utility tunnel is sheared, a three-dimensional numerical model for soil and underground utility tunnel was established in this paper, the longitudinal uneven settlement of the utility tunnel segment was simulated by applying displacement, and the stress distribution law of the bell and spigot joint was obtained. Finally, the relationship between segmental settlement and joint shear loading capacity was established, and the ultimate settlement displacement of precast utility tunnel was obtained. The results show that: When the precast utility tunnel segment is sheared, the medial compression and lateral tension of the utility tunnel segment are caused. The stress at the spigot joint is distributed in the vertical side wall. The stress distribution in the bell roof and floor, the bearing end is mainly subjected to force on both sides of the top and bottom plate. The maximum principal stress of the bell joint is concentrated at the upper 1 m of the side wall, spigot the stress is concentrated in the bottom. The shear stress increases with the settlement increase under the parallel shear condition, while that decreases with the increase of displacement under reverse shear condition. the ultimate shear stress of the bell and spigot joint is 407 kN and 512 kN, The research results provide a scientific basis for the utility tunnel project engineering safe operation.

To deeply analyze the stiffness and failure mode of composite beams under the combined action of SMW construction shaped steel and cement soil, the article measured the deflection of steel-cement soil composite beams during the bending process through indoor experiments and simulated the behavior using ABAQUS finite element software. Comparative analysis showed that the friction contact element was more reasonable in simulating the steel-cement soil contact relationship. On the basis of verifying the model, the specific effects of factors such as the friction coefficient of the steel cement soil contact surface and the strength of the cement soil on the stiffness changes of the composite structure were further explored. The results show that the frictional contact element can more accurately reflect the actual contact behavior and has a high degree of agreement with experimental data; The greater the interaction between steel and cement soil, the greater the overall stiffness of the composite beam; Under the same load, the stiffness of steel-cement soil composite beams will increase with the increase of cement soil strength.