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黏土在低水力坡降下偏离达西定律的现象及应力历史对土体变形的影响已为人们所认识,但能够同时考虑非达西渗流及应力历史影响的土体固结理论还很鲜见。在传统太沙基一维固结理论基础上,引入经典的Hansbo渗流模型,并考虑土体在不同应力状态下的变形特性,建立实际变荷载作用下土体的非线性固结模型。利用有限差分法对模型进行数值求解。在保证数值解可靠性的基础上,着重分析非达西渗流对超固结土固结性状的影响及非达西渗流下应力状态对固结性状的影响,并分析比较其异同点。结果表明:非达西渗流下超固结土的固结速率要比达西定律下慢,且随非达西渗流模型参数m、i_1值的增大,固结速率的减慢愈加明显;对考虑非达西渗流的不同应力状态土体而言,超固结土的固结速率最快,且超固结土在外荷载作用下产生的地基最终沉降值最小;对考虑非达西渗流的超固结土而言,前期固结压力越大、回弹再压缩指数越小,则土的固结速率越快,地基土的最终沉降值越小。
The phenomenon that clay deviates from Darcy’s law at low hydraulic gradient and the influence of stress history on the soil deformation has been well recognized. However, the theory of soil consolidation, which considers the influence of non-Darcy flow and stress history, is still rare. Based on the traditional one-dimensional consolidation theory of the terrestrial base, a classical Hansbo seepage model is introduced, and the deformation characteristics of the soil under different stress states are considered. The nonlinear consolidation model of the soil under actual variable load is established. The finite difference method is used to solve the model numerically. On the basis of ensuring the reliability of numerical solution, the influence of non-Darcy seepage on the consolidation behavior of overconsolidated soil and the influence of stress state on the consolidation behavior under non-Darcy flow are analyzed. The similarities and differences are analyzed and compared. The results show that the consolidation rate of overconsolidated soil under non-Darcy seepage is slower than that under Darcy’s law, and the slowdown of the consolidation rate becomes more obvious with the increase of m and i_1 values of non-Darcy seepage model. The consolidation rate of overconsolidated soil is the fastest in terms of soil with different stress states considering non-Darcy seepage, and the ultimate settlement value of overconsolidated soil under external load is the smallest. For non-Darcy seepage In terms of consolidated soil, the higher the consolidation pressure in the early stage, the smaller the rebound recompression index, the faster the consolidation rate of soil and the smaller the final settlement of foundation soil.