Time-dependent behavior and permeability evolution of limestone under hydro-mechanical coupling  

作　　者：WANG Zhilong ZENG Zhengqiang LYU Cheng WANG Mingnian HU Xiongyu DONG Yucang 

机构地区：[1]School of Civil Engineering,Southwest Jiaotong University,Chengdu 61003,China [2]College of Civil Engineering,Tongji University,Shanghai 200092,China [3]College of Water Resource and Hydropower,Sichuan University,Chengdu 610065,China [4]Hebei GEO University,Shijiazhuang 050031,China

出　　处：《Journal of Mountain Science》2024年第5期1697-1714,共18页山地科学学报（英文）

基　　金：financially supported by the China Postdoctoral Science Foundation (No. 2023M742898);the Postdoctoral Fellowship Program of CPSF (No. GZC20232193)。

摘　　要：Excessively high pore water pressure presents unpredictable risks to the safety of rock tunnels in mountainous regions that are predominantly composed of limestone. Investigating the creep characteristics and permeability evolution of limestone under varying hydrated conditions is crucial for a better understanding of the delayed deformation mechanisms of limestone rock tunnels. To this end, this paper initially conducts a series of multi-stage triaxial creep tests on limestone samples under varying pore water pressures. The experiment examines how pore water pressure affects limestone’s creep strain, strain rate, long-term strength, lifespan, and permeability, all within the context of hydraulicmechanical(HM) coupling. To better describe the creep behavior associated with pore water pressure, this paper proposes a new nonlinear fractional creep constitutive model. This constitutive model depicts the initial, steady-state, and accelerated phases of limestone’s creep behavior. Finally, the proposed model is applied to the numerical realization of deformation in limestone tunnel, validating the effectiveness of the proposed constitutive model in predicting tunnel’s creep deformation. This research enhances our understanding of limestone’s creep characteristics and permeability evolution under HM coupling, laying a foundation for assessing the longterm stability of mountain tunnels.

关 键 词：Creep test Hydraulic-mechanical coupling Creep constitutive model Fractional derivatives Pore pressure 

分 类 号：U456[建筑科学—桥梁与隧道工程]