Sand columns have been widely used to accelerate drainage and then improving the mechanical properties of soft soil foundations. The sand column has also been introduced into the triaxial test by researchers, in the center of the cylindrical specimen, to greatly accelerate drainage and consolidation process. The objective of this paper is to evaluate the consolidation properties of the triaxial cylindrical specimen considering the presence of a sand column, and then to propose a consolidation model that simulates the consolidation process of the triaxial test. The consolidation equations were derived considering the drainage of the specimen with a sand column composed of both vertical and double‐radial flows. Then the analytical solution of the model was obtained based on specific initial and boundary conditions. The comparison between the consolidation model and the laboratory tests yielded highly consistent. The case study demonstrated that the proposed consolidation model accurately simulates the evolution of average pore pressure and degree of consolidation in triaxial specimens containing a sand column. The studies on the consolidation parameters showed that there were different effects on the drainage rate for the diameter of specimen, the permeability coefficients of specimen and sand column, as well as the radius of the sand column.

中文翻译：

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快速三轴试验中排水固结模型及其解析解


砂柱已被广泛用于加速排水，从而改善软土地基的力学性能。研究人员还将砂柱引入三轴试验中，位于圆柱形试件的中心，以大大加速排水和固结过程。本文的目的是评估考虑砂柱存在的三轴圆柱形试件的固结特性，然后提出模拟三轴试验固结过程的固结模型。固结方程的推导考虑了由垂直流和双径向流组成的砂柱样本的排水。然后根据特定的初始条件和边界条件得到模型的解析解。固结模型与实验室测试的比较结果高度一致。案例研究表明，所提出的固结模型准确地模拟了含有砂柱的三轴样本中平均孔隙压力和固结程度的演变。固结参数研究表明，试件直径、试件与砂柱的渗透系数以及砂柱半径对排水率有不同的影响。