A fractional-order damage creep model for grouting-reinforcement body under dry–wet cycle

• Published in: Bulletin of engineering geology and the environment Vol. 82; no. 5
• Main Authors: Yin, Zhanchao, Zhang, Xiao, Liu, Yanshun, Yu, Hao, Zhang, Qingsong, Li, Xianghui
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2023
• Subjects: Earth and Environmental Science; Earth Sciences; Foundations; Geoecology/Natural Processes; Geoengineering; Geotechnical Engineering & Applied Earth Sciences; Hydraulics; Nature Conservation; Original Paper; Creep behavior; Tunnel operation simulation; Dry–wet cycle; Fractional-order creep model; Grouting-reinforced body
• ISSN: 1435-9529; 1435-9537
• DOI: 10.1007/s10064-023-03196-2

The grouted circle formed by curtain grouting is widely used to mitigate geohazards, including the isolation of groundwater in tunnels. However, few studies have focused on the creep behavior of a grouting-reinforced body under dry–wet (DW) cycles. In this study, uniaxial compressive creep tests were performed to study the time-dependent behavior of grouted specimens with different DW cycles. In addition, a novel nonlinear fractional-order model that considers the DW cycle damage was proposed to describe the creep characteristics of grouted specimens. Finally, a post-grouting tunnel long-term deformation analysis was numerically performed using the proposed model. The following results were obtained. (1) The creep behavior of the grouted specimen undergoes three stages under different loadings, namely decaying creep, steady creep, and accelerated creep. The initial strain and steady creep rate increased as the DW cycles and loading level increased. (2) A fractional-order viscoelastic model coupled with DW cycle damage variables was proposed to describe the creep behavior of a grouting-reinforced body. (3) The creep effect of the grouting circle under DW cycles has a significant influence on tunnel deformation and lining safety (i.e., larger deformation accumulation in the early stage and higher deformation growth rate in long-term operation). This study can be used for future prediction of the long-term deformation of post-grouting tunnels under DW cycle damage, which can help devise maintenance strategies for long-term safety.