LI Shunqun,GUI Chao,and XIA Jinhong.Transient flow in unsaturated soil under the constant air pressure[J].Journal of Shenzhen University Science and Engineering,2018,35(1):70-77.[doi:10.3724/SP.J.1249.2018.01070]





Transient flow in unsaturated soil under the constant air pressure
新乡学院土木工程与建筑学院,河南新乡 453003
LI Shunqun GUI Chao and XIA Jinhong
School of Civil Engineering and Architecture, Xinxiang University, Xinxiang 453003, Henan Province, P.R.China
soil mechanics unsaturated soil constant suction axis-translation transient flow differential principle
TU 441+.33
为揭示非饱和土在气压作用下孔隙水的渗流特征,基于Darcy定律和饱和度与基质吸力、渗透系数之间的经验公式,建立了三轴试样在常气压时的孔压消散方程,基于差分原理建立了该非线性偏微分方程的求解方法. 采用Wykeham Farrance三轴实验系统,利用轴平移技术进行了不同气压作用下非饱和土的失水实验. 结合实验得到的参数和常规物理力学指标,对该高阶非线性偏微分方程进行了求解,并利用有限元软件对三轴试样在常气压作用下的瞬态渗流过程进行了模拟,将实验结果、偏微分方程数值解和有限元计算结果进行了对比分析. 结果表明,实验数据、偏微分方程数值解和有限元计算结果三者吻合较好,所建立的偏微分方程能够刻画非饱和土在常气压力作用下的瞬态渗流过程. 本项研究阐明了轴平移技术的物理本质,进一步完善了非饱和土实验理论.
In order to discover seepage characters of unsaturated soil under air pressure, we establish a partial differential equation for the pore water pressure dissipation of triaxial specimens in terms of Darcy’s law, the empirical formula between permeability coefficient and saturation or matrix suction. Then, we give the solution method for the partial differential equation based on differential principle. After the Wykeham Farrance (WF) unsaturated soil triaxial experiment system is employed, we perform the drying process under matric suction based on the axis-translation technique. Combined with the parameters obtained from the experiment, we solve the higher order nonlinear partial differential equations, and simulate the unsaturated process by finite element method (FEM) at the same time. The results are in a good agreement with the experimental data, the analysis solution and the FEM results. It shows that the established partial differential equation can depict the dissipation process of the unsaturated soil under the effect of air pressure. This study illustrates physical essence of the axis translation technique and may improve the existing experiment theory in unsaturated soil mechanics.


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Foundation:National Natural Science Foundation of China (41472253)
Corresponding author:Professor LI Shunqun. E-mail: lishunqun@sina.com
Citation:LI Shunqun,GUI Chao,XIA Jinhong.Transient flow in unsaturated soil under the constant air pressure[J]. Journal of Shenzhen University Science and Engineering, 2018, 35(1): 70-77.(in Chinese)
作者简介:李顺群(1971—),男,新乡学院客座教授. 研究方向:土力学和基础工程. E-mail: lishunqun@sina.com
引文:李顺群, 桂超, 夏锦红. 常气压下非饱和土的一维瞬态渗流[J]. 深圳大学学报理工版,2018,35(1):70-77.
更新日期/Last Update: 2017-12-22