基于PFC2D黏性土与混凝土接触面剪切试验研究

Research on the Shear Test of Interface Between Cohesive Soil and Concrete Based on PFC2D

基于颗粒离散元理论、单轴及双轴压缩试验可获得混凝土及土体细观强度参数,将其应用到黏性土与混凝土直剪试验中。研究表明:PFC2D软件能够从细微观尺度揭示土体-混凝土两种不同材料界面处剪切破坏机制,直剪试样经历了四阶段,分别为弹性阶段、弹塑性阶段、强度软化阶段及残余强度阶段;接触界面裂纹的快速贯穿是导致强度软化的主因,在直剪试验加载过程中接触界面及离界面较近区域土体会随混凝土一起变形,直至试样达到土体抗剪强度为止。

Based on the particle discrete element theory,uniaxial and biaxial compression tests can be used to obtain the microscopic strength parameters of concrete and soil,which are applied to the straight shear tests of clayey soil and concrete.The study shows that:PFC2D software can reveal the shear damage mechanism at the interface between soil-concrete and two different materials from a fine microscopic scale,and the straight shear specimens experienced four stages,namely the elastic stage,elastic-plastic stage,strength softening stage,and residual strength stage;the rapid penetration of cracks at the interface of the contact is the main cause of the softening of the strength,and the soil will deform along with the concrete during the loading process of the straight shear test,until the specimen reaches the soil body and concrete.During the loading process of the straight shear test,the soil in the contact interface and the area closer to the interface will be deformed together with the concrete until the specimen reaches the soil shear strength.