基于耦合欧拉-拉格朗日法充灌袋挤淤过程的有限元研究

在含水率大、承载能力低的软土地基上，利用充灌砂袋进行挤淤置换的方法工艺简单、施工方便、处理效果明显，已经广泛地应用在建造围埝和修筑道路中。充灌袋下沉到一定深度后，其重量与地基承载力相等，从而达到极限平衡状态。充灌袋挤淤所达到的深度与其高度存在一定的对应关系，在工程中确定此关系十分重要。通过3组不同宽度的挤淤模型试验，得到充灌袋下沉量与充灌袋高度的曲线关系、淤泥的位移特性及隆起量。利用ABAQUS中耦合欧拉-拉格朗日法（CEL法），将充灌袋和淤泥分别用拉格朗日体和欧拉体描述，模拟充灌袋挤淤下沉的过程，将模拟得到的充灌袋下沉深度和高度的关系、淤泥的位移特点与试验结果以及理论公式进行对比。结果表明，CEL法模拟得到的结果与试验结果、理论解具有很好的吻合性，说明利用CEL法可以较好地模拟充灌袋的挤淤问题。

Finite element analysis of penetration depth of geotubes based on coupled Eulerian-Lagrangian method

The displacement method of geotubes is widely applied to improving soft soil with a high water content and low bearing capacity in reclamation dam and road constructions due to its easy construction technology and significant treatment effect. When the weight of the geotubes is equal to the bearing capacity of foundation soil, the soil attains limiting equilibrium condition. It is necessary to estimate the relationship between the penetration depth and height of the geotubes. In this paper, model tests of three widths of geotubes are carried out, and the relationships between penetration depth and height, the displacement and upheavals of soil are revealed. In order to simulate the process of penetration of three geotubes, the Coupled Eulerian-Lagrangian approach(CEL) in ABAQUS software is used to simulates the process of penetration of geotubes. In this simulation, the geotube and silt are described as Lagrangian body and Eulerian body, respectively. The relationships of penetration depth with height of the geotube as well as displacement of the silt are obtained. The accuracy of the simulation approach is verified by model test results and theoretical result, showing that the coupled Eulerian-Lagrangian approach can be applied to predicting the penetration of geotubes very well.