超固结土的广义塑性本构模型

Generalized Plasticity Constitutive Model for Over-consolidated Soil

鉴于目前超固结土本构模型不能较好地反映土体的实际变形,基于广义塑性理论并引入伏斯列夫面及超固结参数的概念,建立了一个可以反映超固结土变形特性的广义塑性本构模型,该模型采用能较好反映试验资料的Lagioia剪胀方程,在此基础上推导出超固结参数、塑性流动和加载方向张量,并构造了一个可以较好反映土体变形特性的塑性模量,且基于SMP变换应力法将模型三维化,使其能适用于一般应力状态。根据试验资料获得饱和Fujinomori粘土的本构模型参数,利用新的模型编制程序预测超固结土的变形特性,发现预测结果与试验数据吻合较好,表明新的模型可以合理地反映超固结土的变形特性。

As the pre-existing constitutive model cannot reflect deformation properties of over-consolidated soil,a generalized plasticity constitutive model which was induced the Hvorslev surface and over-consolidated parameter was established.The over-consolidated parameter,the plastic flow direction and the loading direction were formulated based on the Lagioia dilatancy equation which can better fit the test data.And then,a new plastic modulus which can reflect deformation properties was established.Moreover,to adapt to the general stress status,the model was converted to a threedimensional format by using the SMP method.The prediction of the proposed model is consistent with the test result of saturated Fujinomori clay by compiling programs for the above model,and the validation of the model was testified.