Study of hydro-mechanical behaviours of rough rock fracture with shear dilatancy and asperities using shear-flow model  

作　　者：Luyu Wang Weizhong Chen Qun Sui 

机构地区：[1]Department of Civil and Environmental Engineering,The Hong Kong Polytechnic University,Hung Hom,Kowloon,Hong Kong,China [2]Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,430071,China [3]Changjiang Design Group Co.,Ltd.,Wuhan,430010,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第10期4004-4016,共13页岩石力学与岩土工程学报（英文）

基　　金：support from the National Natural Science Foundation of China(Grant Nos.51991392 and 42293355).

摘　　要：The geometric properties of fracture surfaces significantly influence shear-seepage in rock fractures,introducing complexities to fracture modelling.The present study focuses on the hydro-mechanical behaviours of rough rock fractures during shear-seepage processes to reveal how dilatancy and fracture asperities affect these phenomena.To achieve this,an improved shear-flow model(SFM)is proposed with the incorporation of dilatancy effect and asperities.In particular,shear dilatancy is accounted for in both the elastic and plastic stages,in contrast to some existing models that only consider it in the elastic stage.Depending on the computation approaches for the peak dilatancy angle,three different versions of the SFM are derived based on Mohr-Coulomb,joint roughness coefficient-joint compressive strength(JRC-JCS),and Grasselli’s theories.Notably,this is a new attempt that utilizes Grasselli’s model in shearseepage analysis.An advanced parameter optimization method is introduced to accurately determine model parameters,addressing the issue of local optima inherent in some conventional methods.Then,model performance is evaluated against existing experimental results.The findings demonstrate that the SFM effectively reproduces the shear-seepage characteristics of rock fracture across a wide range of stress levels.Further sensitivity analysis reveals how dilatancy and asperity affect hydraulic properties.The relation between hydro-mechanical properties(dilatancy displacement and hydraulic conductivity)and asperity parameters is analysed.Several profound understandings of the shear-seepage process are obtained by exploring the phenomenon under various conditions.

关 键 词：Rock fracture Stress-seepage coupling Shear-flow model Fracture asperity Shear dilatancy 

分 类 号：TU45[建筑科学—岩土工程]