考虑非达西渗流的双层软土地基大变形非线性固结分析

发布时间：2018-03-11 16:31

本文选题：双层地基　切入点：非达西渗流　出处：《岩土力学》2016年08期 　论文类型：期刊论文

【摘要】：现有的双层软土地基大变形固结理论均假定土中渗流遵循达西定律,但软黏土中渗流在低水力坡降下会出现偏离达西定律的现象已逐渐为人们认识。综合考虑双层软黏土中的非达西渗流、软土的非线性压缩渗透特性及实际中的变荷载作用,在拉格朗日坐标系中建立以超静孔压为变量的软土大变形非线性固结模型,并给出其有限差分解。在此基础上,通过与已有的非达西定律下单层地基大变形固结数值解计算结果相对比,以验证其差分解的可靠性。最后着重分析上、下层非达西渗流参数m_1、i_(11)及m_2、i_(12)对固结性状的影响,并分析了在大、小变形不同几何假定下对双层地基超静孔压消散及固结沉降影响的异同。结果表明:上层土参数m_1、i_(11)对固结性状的影响要比下层土参数m_2、i_(12)显著;m_2、i_(12)的增大会引起上层土超静孔压消散速率的加快,但双层地基的固结速率会减慢;大变形假定下双层软土地基的固结速率要比小变形假定下快,但两种几何假定下双层地基的最终沉降量是相等的。
[Abstract]:The existing consolidation theory of large deformation of double-layer soft soil foundation assumes that the seepage in soil obeys Darcy's law. However, the phenomenon that seepage in soft clay deviates from Darcy's law under low hydraulic gradient has been gradually recognized. Considering the non Darcy seepage in double layer soft clay, the nonlinear compressive permeability of soft clay and the effect of variable load in practice are considered. In Lagrangian coordinate system, a nonlinear consolidation model for large deformation of soft soil is established, in which the excess pore pressure is taken as a variable, and its finite difference decomposition is given. The reliability of the differential decomposition is verified by comparing the results with the numerical solution of large deformation consolidation of single-layer foundation under non-Darcy 's law. Finally, the influence of non-Darcy percolation parameters m1i _ (11) and m _ 2i _ (12) on the consolidation behavior is analyzed. And analyzed in the big, The effects of different geometric assumptions of small deformation on the dissipation of excess static pore pressure and consolidation settlement of double-layer foundation are similar and different. The results show that the effect of the upper soil parameter m _ 1 / I _ (11)) on consolidation behavior is more significant than that of the lower soil parameter m _ 2i _ (12) (m _ 2i _ I _ (12)) and the increase of the upper layer will result in the increase of the upper layer. The acceleration of dissipation rate of soil excess pore pressure, But the consolidation rate of double-layer foundation will slow down, the consolidation rate of double-layer soft soil foundation is faster than that of small deformation assumption, but the final settlement of double-layer foundation is equal under two geometric assumptions.
【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) 中国博士后基金面上项目(No.2013M530237);中国博士后基金第七批特别资助项目(No.2014T70479)~~
【分类号】：TU447

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