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引入控敛因子θ,提出能克服邓肯–张模型数学缺陷的延拓模型,证明邓肯–张模型是延拓模型在θ=2时的特例,并揭示延拓模型更适用于模拟具有强烈非线性变形行为的滨海相软土。基于传统的邓肯–张模型和新建的延拓模型,采用C++语言编制二维有限元程序,对滨海相软土常规三轴压缩试验进行数值模拟研究。研究结果表明:当初始切线模量和极限偏应力为定值时,控敛因子与延拓模型曲线的收敛速度呈负相关;延拓模型可通过改变控敛因子来模拟收敛速度大于或小于邓肯–张模型的应力–应变曲线;在轴向应变相同的情况下,减小控敛因子,会导致试样各单元的轴向应力值和中部单元的径向应变值增大,试样部分单元最小安全系数减小;同一围压下,控敛因子与体积应变呈负相关;围压越大,控敛因子对体积应变的影响也越大。
By introducing the convergence factor θ, a continuation model that can overcome the mathematical defects of the Duncan - Chang model is proposed. It is proved that the Duncan - Zhang model is a special case of the continuation model at θ = 2 and reveals that the continuation model is more suitable for simulating a nonlinear model with strong nonlinearity Deformation of coastal soft facies. Based on the traditional Duncan-Zhang model and the new continuation model, a two-dimensional finite element program was compiled by using C ++ language to simulate the conventional triaxial compression tests of the soft clay in the coastal area. The results show that when the initial tangent modulus and the ultimate deviatoric stress are constant, the convergence rate is negatively correlated with the convergence rate of the continuation model curve. The continuation model can simulate the convergence rate greater or less than Duncan - Zhang model stress-strain curve; in the case of the same axial strain, reducing the convergence factor, will result in each sample axial stress value and the central unit of the radial strain value increases, the sample part of the unit The minimum safety factor decreases. Under the same confining pressure, the convergence factor is negatively correlated with the volumetric strain. The larger the confining pressure, the greater the influence of the convergence factor on the volumetric strain.