基于k0固结条件的淤泥土排水蠕变特性试验研究

Drained creep characteristic of silt soil based on k_0 consolidation

通过k_0固结蠕变试验探讨饱和淤泥土在轴向加载和侧向减载条件下的蠕变特性。由试验数据知:排水条件下,两种应力路径的轴向蠕变规律基本一致,体积应变明显小于轴向应变,且随时间的延长呈现一定程度的剪缩与剪胀交替性。Merchant和Burgers蠕变模型对淤泥土都有较好拟合精度。二者的蠕变参数E_K、η_K、η_M均呈现随应力水平的增大而减小的变化规律,E_M随应力水平的变化则较为平稳,无明显增大或减小趋势,说明淤泥土的蠕变变形受黏弹模量影响较小,受土体黏滞系数及弹性模量影响较大。

The creep characteristic of saturated silt soil was studied through k0 consolidation creep tests under the conditions of axial loading and lateral lightening. The following results were found. First, the axial creep patterns of the two stress paths were basically consistent under the drainage conditions. The volume strains were much smaller than the axial strains. The volume strains showed an alternation between shear shrinkage and shear dilatancy with the passage of time. The Merchant and Burgers creep models both had good fitting accuracy. The creep parameter EM showed no significant increasing or decreasing trend with the increase of deviatoric stress level, but the other creep parameters EK, ηK, ηM of the two creep models decreased with the increase of deviatoric stress level. These findings suggested that the creep strain of silt soil is mildly influenced by viscoelastic modulus, but largely influenced by the viscous coefficient and elastic modulus.