Partial collapse mechanism of a horseshoe-shaped tunnel face in layered soils

• Published in: Computers and geotechnics Vol. 167; p. 106114
• Main Authors: Wang, Saixu, Zhang, Chengping, Li, Wei, Tu, Shiqin, Wang, Libin, Jin, Zixian
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2024
• Subjects: 3D failure mechanism; Layered soils; Limit analysis; Partial collapse; Tunnel face stability; Partial collapse; Tunnel face stability; Limit analysis; Layered soils; 3D failure mechanism
• ISSN: 0266-352X; 1873-7633
• DOI: 10.1016/j.compgeo.2024.106114

Layered soils are becoming increasingly common in tunnel construction. In order to investigate the stability of horseshoe-shaped tunnel face in layered soils, a rotational partial failure mechanism is presented, considering the conditions for the occurrence of partial failure. A series of numerical simulation models provide essential data required to predict the shape of the mechanism. The upper-bound limit analysis method and the spatial discretization technique is adopted so that collapse pressure and the estimated collapse zone can be got. Subsequently, the obtained results from the proposed mechanism with those derived from numerical models and existing approaches is contrasted, verifying the accuracy the superiority of the mechanism in analyzing the stability of horseshoe-shaped tunnel face. Finally, size effect is analyzed to provide reference for large-diameter shield engineering.