考虑非达西渗流和应力历史的土体非线性固结研究

发布时间：2018-04-01 02:17

本文选题：应力历史　切入点：非达西渗流　出处：《岩土力学》2017年01期

【摘要】：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。
[Abstract]:The phenomenon of clay deviating from Darcy's law under low hydraulic slope and the influence of stress history on soil deformation have been recognized. But the soil consolidation theory which can consider the influence of non-Darcy seepage and stress history at the same time is rare. On the basis of the traditional one-dimensional consolidation theory of Terzaghi, the classical Hansbo seepage model is introduced, and the deformation characteristics of soil under different stress states are taken into account. The nonlinear consolidation model of soil under actual variable load is established. The finite difference method is used to numerically solve the model. On the basis of ensuring the reliability of the numerical solution, The influence of non-Darcy seepage flow on consolidation behavior of overconsolidated soil and the influence of stress state on consolidation behavior under non-Darcy seepage are analyzed. The results show that the consolidation rate of overconsolidated soil under non-Darcy seepage is slower than that under Darcy's law, and the decrease of consolidation rate becomes more obvious with the increase of the parameter mi _ 1 of non-Darcy seepage model. For soils with different stress states considering non-Darcy seepage, the consolidation rate of the overconsolidated soil is the fastest, and the final settlement value of the foundation produced by the overconsolidated soil under external load is the smallest, and for the overconsolidated soil considering non-Darcy seepage, The higher the preconsolidation pressure and the smaller the springback and recompression index, the faster the consolidation rate of the soil and the smaller the final settlement value of the foundation soil.
【作者单位】：江苏大学土木工程与力学学院;浙江大学滨海和城市岩土工程研究中心;
【基金】：国家自然科学基金项目(No.51109092,No.11272137) 中国博士后基金项目(No.2013M530237,No.2014T70479)~~
【分类号】：TU43

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