We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
A practical method for considering soil strain softening effect in the tunnel face stability analysis by numerical modeling.
- Authors
Sun, Minghui; Yan, Qixiang; Zhang, Junchen; Wang, Erli; Yao, Chaofan; Wang, Xinqiang
- Abstract
Face stability is one of the major concerns during shield tunneling. Many researchers have performed numerical analysis for tunnel face stability of shield tunneling in sandy soil. Soil strain softening effect is worthy of attention in tunnel face stability analysis in the sandy soil stratum, which was overlooked in previous studies by numerical simulation. The paper aims to provide a practical method to simulate the soil strain softening effect for tunnel face stability analysis. The elastoplastic Mohr–Coulomb constitutive model with isotropic strain softening (MCS) was extended in the finite element program to model the sandy soil by user subroutine. A series of cases were simulated, with different tunnel diameters and cover-to-diameter ratios. The simulation results are compared for the models using the practical method and the conventional elastoplastic Mohr–Coulomb constitutive model (MC). The former shows more consistent results with the existing experiments than the latter. The predicted relationships between the minimum required support pressure (MRSP) and the tunnel diameter are similar. The soil failure zone geometries predicted by the two models are analogous as well. The variation of the MRSP with the cover-to-diameter ratio predicted using the MCS more accords with the experiments, reflecting the soil arching effect. A novel tunnel face collapse mechanism is summarized: The tunnel face collapse in sandy soil is due to the growth of the failure zone and the decrease of shear strength in the softened zone.
- Publication
Bulletin of Engineering Geology & the Environment, 2022, Vol 81, Issue 11, p1
- ISSN
1435-9529
- Publication type
Article
- DOI
10.1007/s10064-022-02985-5