Mechanical Response Characteristics of Prefabricated Utility Tunnel Joints Considering Jacking Load Imbalance

During jacking construction of prefabricated utility tunnels, asynchronous jack output and interface friction may induce internal force redistribution and deformation amplification at the leading end. Taking a triple-cell prefabricated utility tunnel in Xiong’an New Area as a case study, a three-dimensional finite element model was established considering inter-segment contact, equivalent bolted connections, and bottom-slab-bedding friction. Jack asynchrony was idealized as a quasi-static thrust imbalance, and a synchronous case, asynchronous cases with thrust differences of 5–30%, and varying friction coefficients were analyzed. For the 30% thrust-difference condition, structural responses were examined at both the gasket-compression stage and the maximum jacking-force stage. The results show that jacking loads attenuate along the tunnel length in a staged manner, with the leading end acting as the primary load-transfer zone. Increasing thrust imbalance drives the response from axial compression toward eccentric compression-bending, accompanied by monotonic increases in principal stresses and vertical displacement. Higher friction further amplifies the leading-end response; nevertheless, for the investigated configuration, stresses and deformations under a 30% thrust imbalance remain within engineeringly acceptable limits. The findings provide a basis for identifying critical leading-end locations, arranging monitoring schemes, and supporting construction control under asynchronous jacking.