冻土弹塑性各向异性损伤模型及其损伤分析  

AN ELASTOPLASTIC ANISOTROPIC DAMAGE MODEL FOR FROZEN SOIL AND ITS DAMAGE ANALYSIS

作　　者：孙星亮[1] 汪稔[2] 胡明鉴[2] 

机构地区：[1]石家庄铁道学院土木工程分院,河北石家庄050043 [2]中国科学院武汉岩土力学研究所,湖北武汉430071

出　　处：《岩石力学与工程学报》2005年第19期3517-3521,共5页Chinese Journal of Rock Mechanics and Engineering

基　　金：中国科学院知识创新重大工程项目(KZCX1–SW–04)

摘　　要：基于不可逆热力学理论,通过引入能考虑冻土体积变形的塑性势函数,得到冻土弹塑性各向异性损伤本构方程,在与损伤张量对偶的广义力——应变能释放率空间中,构造了损伤累积势函数,并导出各向异性损伤演化方程。应用此模型分析冻土三轴试验资料,计算结果与试验吻合较好。计算结果表明:(1)冻土变形过程中的弹性损伤只占总损伤量的很小一部分,绝大部分损伤发生在塑性变形阶段;(2)围压的增大,有助于冻土结构的强化,从而减少冻土结构的总损伤量。On the basis of irreversible thermodynamic theory, an elastoplastic anisotropic damage constitutive model is presented by introduction of a plastic potential function considering the volume change of frozen soil. The anisotropic damage evolution equation is derived from the damage accumulated potential function, which is constructed in the space of the damage strain energy release rate that is conjugated with damage tensor. Triaxial tests are chosen to illustrate the application of this model, and good agreement between experimental data and numerically simulated ones is obtained. The calculated results indicate that the amount of elastic damage only accounts for a small percentage of total structural damage of frozen soil, and most part of damage takes place during the plastic deformation phase. The increase in confining stress can strengthen the structure and reduce the amount of total damage of frozen soil.

关 键 词：土力学 冻土 弹塑性 各向异性损伤 损伤演化 

分 类 号：TU445[建筑科学—岩土工程]