3D computational study of tunnel segment behaviour under loading by TBM thrust jacks

ABSTRACT

This study presents the numerical modelling of tunnel segments under thrust loads of an EPB shielded TBM that utilised in Tabriz metro, Iran. Finite element analysis was used for 3D numerical investigations. Three different types of thrust jack configuration including French, German, and Japanese were applied to the segments and their results were compared. The numerical results indicate that the segment cracks are mainly concentrated in the circumferential joints in the French and Japanese configurations while the German configuration has the possibility of crushing in the longitudinal joints. By applying the maximum thrust load, the smallest tensile cracking area was observed in the Japanese configuration in comparison to the others. In the French and German configuration under the maximum thrust load, cracks were developed at the furthest point from the loading surface. Under the minimum thrust load, no crack appears in the Japanese configuration, while tensile cracks were initiated in the French and German configuration under the same load. Furthermore, the mechanical behaviour of the reinforced concrete (RC) was compared with plain concrete under various thrust loading configurations. Finally, the results of the numerical modelling are compared with the field observations for verifying of them.

KEYWORDS:

• Jacking configuration
• reinforced concrete
• thrust jack
• 3D modelling
• segmental lining
• Tabriz Metro

Disclosure statement

No potential conflict of interest was reported by the authors.