Research on the Development of Shield Tunnel Invert-Filling Disengaging Caused by Surcharge Load

In this study, a three-dimensional calculation model of the staggered assembly of a shield tunnel was established to investigate the impact of the surface surcharge load on invert-filling disengaging of a shield tunnel. The accuracy of the modeling method was confirmed through a full-scale test. This model was used to analyze the invert-filling disengaging process under various surcharge loads, and investigate the relationship among shield tunnel settlement, deformation, and invert-filling disengaging indicators (disengaging ratio and invert-filling separation). The findings demonstrate that, (1) along with the tunnel's convergence deformation, the disengaging ratio and invert-filling separation have the characteristics of being large in the middle and small at both ends. The tunnel settlement because of the surcharge load follows a Gaussian distribution. (2) The disengaging ratio and invert-filling separation are correlated, and the logarithmic function and the BiDoseResp function can be used to explain this correlation. As the separation widens, the disengaging ratio's development becomes more variable. The disengaging ratio development trend was gradually approached when the separation reached approximately 2-3 mm. (3) The relationship between the tunnel settlement, deformation, and two invert-filling indicators can be described by a polynomial.

Automated summary

In this study, a three-dimensional calculation model was established to investigate the impact of surface surcharge load on invert-filling disengaging of a shield tunnel. The accuracy of the model was confirmed through a full-scale test. The relationship among shield tunnel settlement, deformation, and invert-filling disengaging indicators was analyzed using this model, and it was found that there are correlations and certain trends among them.