考虑非线性流变的一维修正UH模型

考虑到饱和黏性土流变的非线性特点,假定次固结系数是时间对数的双曲线函数,提出一种修正的次固结计算式,并基于这种思想修正统一硬化(UH)本构模型. 为验证修正UH本构模型的有效性,以河南某地重塑黏性土为例,进行一维单面排水流变固结试验. 结果表明,在按Cassagrande方法确定的主固结完成时,土样中仍有一定的孔隙水压力有待消散. 应用修正UH本构模型对不同荷载等级下试验结果进行的模拟表明,该模型能够较好地拟合试验结果. 最后,为进一步验证修正UH模型的适用性,又对文献中的一些固结试验结果进行模拟.

One-dimensional modified UH constitutive model considering nonlinear rheological behavior

In view of the nonlinear rheological characteristics of saturated clayey soil, the secondary consolidation coefficient was assumed as a hyperbolic function of the logarithm of time, and a modified secondary consolidation equation was proposed. Based on this idea, the unified hardening (UH) constitutive model was modified. To verify the effectiveness of the modified UH constitutive model, by taking a kind of reconstituted clayey soil in Henan province as an example, a series of one-dimensional rheological oedometer tests with one-way drainage were carried out. Test results illustrate that there was still some pore water pressure to be dissipated in the soil sample, when the primary consolidation determined by the Cassagrande method was completed. Then, the modified UH constitutive model was applied to simulate the measured data obtained at different loading stages, and results show that the model could fit the data well. Finally, in order to further verify the applicability of the model, some oedometer test results reported in the literature were simulated.