Abstract:

Due to the complex conformation of joint surface, the significant volume effect of segments, the prominent longitudinal and transverse spatial effect of lining structures, as well as the sensitivity to water pressure and complex strata, and the unstable structure during assembly, the traditional calculation methods could not accurately cope with the structural analysis of shield tunnels with large crosssection. In view of this, the key point of the integrated analysis summarized as "accurately obtaining local parameters, correctly characterizing the overall structure, and precisely reflecting the interaction" is proposed against the structural characteristics of large crosssection shield tunnels. The integrated analysis method of large crosssection shield tunnels is established. Its main technical contents include: accurately obtaining the joint stiffness of segment joint surface, establishing a multibody analysis model reflecting the characteristics of stratumsegment structuregroundwater, comprehensively considering the load system of load evolution during operation and construction, and using iterative analysis method to accurately calculate the internal force and deformation of the structure. The model tests, fullscale tests, prototype tests, in-situ tests, and other multi-level tests show that the method can accurately reflect the mechanical effects of high water-pressure, multi-body contact, grouting layer, and construction stage, and can achievehighprecision analysis. The integrated analysis method for shield tunnel structure has been incorporated into the national design code, Standard for Design of Shield Tunnel Engineering (GB/T 51438-2021), and is required for structural analysis of large cross-section and special shield tunnels.

Key words:

shield tunnel with large cross-section; segmental lining structure, integrated analysis method, verification with multiple types of tests