This paper describes a new approach to modelling the three-dimensional (3D) variability of soil by using a multi-material 3D printer to extrude slurries of different types of clays. First, a distribution of the liquid limit in space was obtained using random field theory. Then, a 3D clay printer was developed to reproduce the complex patterns obtained analytically. The 3D clay printer can use eight types of homogeneous soils made from mixtures of kaolin, bentonite and colourant. The next step was fine-tuning of printing velocity and optimal water content for each type of clay. Consolidation involved two stages: use of a rigid plate to impose low stresses followed by use of a flexible membrane to control the stress rather than displacement during the consolidation process. The variability of the sample built-up with the 3D printer was assessed by measuring the undrained strength and electrical resistivity. Then the electrical resistivity was correlated with porosity. The results showed the differences between probability distributions of each soil's properties including liquid limits, electrical resistance, porosity and undrained shear strength. These differences are results of the consolidation process that tends to homogenise the sample and the failure mode of the experimental method used to evaluate the sample.

中文翻译：

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使用 3D 打印机再现土壤的固有可变性

本文介绍了一种通过使用多材料 3D 打印机挤出不同类型粘土的泥浆来模拟土壤三维 (3D) 可变性的新方法。首先，使用随机场理论获得了空间中液限的分布。然后，开发了 3D 粘土打印机来重现分析获得的复杂图案。3D 粘土打印机可以使用八种由高岭土、膨润土和着色剂混合物制成的均质土壤。下一步是微调每种粘土的印刷速度和最佳含水量。固结涉及两个阶段：使用刚性板施加低应力，然后在固结过程中使用柔性膜来控制应力而不是位移。通过测量不排水强度和电阻率来评估使用 3D 打印机构建的样品的可变性。然后电阻率与孔隙率相关。结果显示了每种土壤特性的概率分布之间的差异，包括液限、电阻、孔隙率和不排水剪切强度。这些差异是趋于使样品均质化的固结过程和用于评估样品的实验方法的失效模式的结果。孔隙率和不排水剪切强度。这些差异是趋于使样品均质化的固结过程和用于评估样品的实验方法的失效模式的结果。孔隙率和不排水剪切强度。这些差异是趋于使样品均质化的固结过程和用于评估样品的实验方法的失效模式的结果。