Study on crack law of shield segment under load variation based on XFEM

Abstract

Purpose

The occurrence of segment cracks caused by load changes in shield tunnels would affect the safety of the tunnel structure. To this end, a three-dimensional fine shield tunnel segment model based on the extended finite element method (XFEM) is established.

Design/methodology/approach

The cracking law of shield segment cracks is studied in two forms: overloading and unloading. The relationship between crack length, width and depth and transverse convergence and deformation is analyzed.

Findings

The results show that the cracks in shield tunnels mainly occur on the outer side of the arch waist and the inner side of the crown and bottom. Under overloading and unloading conditions, the length, width and depth of cracks increase non-linearly as the transverse convergence deformation increases. Under the same convergent deformation, the deeper the buried depth, the smaller the crack length, width and depth. Meanwhile, under overloading conditions, the influence of buried depth on the width and depth of cracks is more significant. In terms of crack width and depth, unloading conditions are more dangerous than overloading conditions.

Originality/value

The findings have a guiding effect for the management of cracks in shield tunnels during operation.

Citation

Guo, H., Niu, X. and Xie, Z. (2024), "Study on crack law of shield segment under load variation based on XFEM", International Journal of Structural Integrity, Vol. 15 No. 5, pp. 1012-1026. https://doi.org/10.1108/IJSI-03-2024-0052