A study of the kaolin electro-osmotic consolidation characteristics and their numerical simulation
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摘要:
电渗固结是促进低渗透性软土排水固结的有效方法。为了揭示不同电势梯度影响高岭土电渗固结的基本规律，在自制电渗试验装置上对高岭土进行电渗试验。试验过程中测量电流、排水量、沉降量以及有效电压随时间的变化，并进行单位排水能耗分析。基于电渗固结多场耦合控制方程，实现土体电渗固结全耦合分析的有限元数值方法，计算结果与解析解吻合良好，验证了程序的有效性。为预测不同电势梯度下土体沉降量随时间的变化关系，分别对0.5，1.0，1.5 V/cm 3种电势梯度电渗固结试验进行数值模拟分析，获得模型表面沉降量分布、阳极超静孔隙水压力时空发展规律、阳极位置固结度等曲线，计算结果和试验结果吻合良好，可为实际电渗试验提供理论指导。
Abstract:Electro-osmotic consolidation is an effective way to promote consolidation of soft soil with low permeability. In order to investigate the basic law of electro-osmotic consolidation behavior of soft clay under different potential gradients, electro-osmotic tests are carried out for kaolin with a self-made device. Changes of current, displacement, settlement and potential with time are measured during the tests, and energy consumption per unit drainage is also analyzed. Based on the electro-osmosis consolidation coupling governing equations, the electro-osmosis of soil consolidation full coupling analysis of finite element programs is developed. The finite element program is developed to examine the fully coupled soil electro-osmotic consolidation behavior based on the multi-field coupling governing equations of electro-osmotic consolidation. The numerical analysis is in good agreement with the analytical results, which proves the efficiency of the program. To predict the settlement of soft clay with time under different potential gradients, numerical analysis is performed to study the electro-osmosis consolidation tests of kaolin clay under three potential gradients: 0.5, 1.0 and 1.5 V/cm, respectively. Numerical simulation analysis for the surface subsidence distribution model, the space-time development of anode excess pore water pressure, and the degree of consolidation of the anode are performed. The numerical analysis results for the settlement are in good agreement with those obtained from the experiments. The results can provide theoretical guidance for practical electro-osmosis tests.
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Key words:
- electro-osmosis tests /
- potential gradients /
- consolidation tests /
- numerical analysis
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