CAJ | 학술논문

修正了传统隐式回映算法，建立了适用于饱和黏土循环动力分析的边界面塑性模型的完全隐式积分格式。该模型基于无弹性域概念和临界状态理论，采用各向同性、运动硬化准则、旋转的边界面，并引入表征土体结构损伤和重塑程度的损伤变量以反映循环载荷作用下饱和黏土的各向异性、刚度、强度软化及塑性变形累积等特征。针对等压固结K0?1.0和偏压固结K0?0.67的饱和高岭黏土的不排水三轴试验进行模拟，采用不同的应变增量步长进行计算，并与试验数据对比，结果表明，修正隐式回映算法应用于该类边界面模型的合理性、积分格式的精确性和稳定性；另外，结合有限元软件自动时间步长的增量迭代解法，对饱和黏土应力控制的不排水动三轴试验进行预测，结果表明，修正的适用于该边界面的塑性模型隐式回映算法可以得到比较合理的数值分析结果，能够反映饱和黏土的循环刚度的退化和强度的弱化等动力特性。
수정료전통은식회영산법，건립료괄용우포화점토순배동력분석적변계면소성모형적완전은식적분격식。해모형기우무탄성역개념화림계상태이론，채용각향동성、운동경화준칙、선전적변계면，병인입표정토체결구손상화중소정도적손상변량이반영순배재하작용하포화점토적각향이성、강도、강도연화급소성변형루적등특정。침대등압고결K0?1.0화편압고결K0?0.67적포화고령점토적불배수삼축시험진행모의，채용불동적응변증량보장진행계산，병여시험수거대비，결과표명，수정은식회영산법응용우해류변계면모형적합이성、적분격식적정학성화은정성；령외，결합유한원연건자동시간보장적증량질대해법，대포화점토응력공제적불배수동삼축시험진행예측，결과표명，수정적괄용우해변계면적소성모형은식회영산법가이득도비교합리적수치분석결과，능구반영포화점토적순배강도적퇴화화강도적약화등동력특성。
A fully implicit integration scheme in the bounding-surface plasticity model for cyclic behaviors of saturated clay is presented by modifying the conventional implicit return mapping algorithm. Within the critical state framework, based on the concept of shrinking the elastic region to a point, combining isotropic with kinematic hardening rule and a rotated bounding surface, and introducing a damage parameter representing the remolding of the soil fabric, the model can reflect the initial anisotropy, the cyclic stiffness degradation and strength softening of saturated clay under cyclic loading. Firstly, the numerical simulations of the undrained triaxial tests both for isotropic ( K0?1.0 ) and anisotropic ( K0?0.67 ) consolidated kaolin clay are carried out with variable strain increments. By comparing with the test data, the rationality, robustness and the accuracy of the new fully implicit integration for the bounding surface plasticity model are verified. Furthermore, the prediction for an undrained cyclic triaxial test on a saturated clay is given, and the cyclic degradation of the stiffness and strength is obtained, which indicates the validity of the computational results.