An elasto-plastic and viscoplastic damage constitutive model for dilatancy and fracturing behavior of soft rock squeezing deformation  

作　　者：HUANG Xing LIU Quan-sheng BO Yin LIU Bin DING Zi-wei ZHANG Quan-tai 

机构地区：[1]State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China [2]Key Laboratory of Geotechnical and Structural Engineering Safety of Hubei Province,School of Civil Engineering,Wuhan University,Wuhan 430072,China [3]College of Energy Engineering,Xi'an University of Science and Technology,Xi'an 710054,China

出　　处：《Journal of Mountain Science》2022年第3期826-848,共23页山地科学学报（英文）

基　　金：financially supported by the National Natural Science Foundation of China(Grant No.52074258,Grant No.41941018,Grant No.51974289,and Grant No.51874232);the Natural Science Basic Research Program of Shaanxi Province(Shaanxi Coal and Chemical Industry Group Co.,Ltd.Joint Fund Project,Grant No.2021JLM-06);the open project of State Key Laboratory of Shield Machine and Boring Technology(Grant No.E01Z440101)。

摘　　要：Soft rock squeezing deformation mainly consists of pre-peak damage-dilatancy and post-peak fracture-bulking at the excavation unloading instant,and creep-dilatancy caused by time-dependent damage and fracturing.Based on the classic elastoplastic and Perzyna over-stress viscoplastic theories,as well as triaxial unloading confining pressure test and triaxial unloading creep test results,an elastoplastic and viscoplastic damage constitutive model is established for the short-and long-term dilatancy and fracturing behavior of soft rock squeezing deformation.Firstly,the criteria for each deformation and failure stage are expressed as a linear function of confining pressure.Secondly,the total damage evolution equation considering time-dependent damage is proposed,including the initial damage produced at the excavation instant,in which the damage variable increases exponentially with the lateral strain,and creep damage.Thirdly,a transient five-stages elasto-plastic constitutive equation for the short-term deformation after excavation that comprised of elasticity,pre-peak damage-dilatancy,post-peak brittle-drop,linear strain-softening,and residual perfectly-plastic regimes is developed based on incremental elasto-plastic theory and the nonassociated flow rule.Fourthly,regarding the timedependent properties of soft rock,based on the Perzyna viscoplastic over-stress theory,a viscoplastic damage model is set up to capture creep damage and dilatancy behavior.Viscoplastic strain is produced when the stress exceeds the initial static yield surface fs;the distance between the static yield surface fs and the dynamic yield surface fd determines the viscoplastic strain rate.Finally,the established constitutive model is numerically implemented and field applied to the-848 m belt conveyer haulage roadway of Huainan Panyidong Coal Mine.Laboratory test results and in-situ monitoring results validate the rationality of the established constitutive model.The presented model takes both the transient and time-dependent damage and fracturi

关 键 词：Soft rock Squeezing deformation Damage DILATANCY FRACTURING Elasto-plastic and viscoplastic damage constitutive model 

分 类 号：TU45[建筑科学—岩土工程]