The Soil Water Characteristic Curve for 3D Printed Soil Samples

The soil water characteristic curve (SWCC), also called water retention curve, is a critically important feature which helps us to understand the behaviour of unsaturated soils. There are many challenges involved in the experimental measurements of SWCC such as difficulties in soil sample preparation, performing the test for different confining pressures, and inaccessibility to soil samples. This study utilizes the combined techniques of micro-focus computed tomography (CT) and 3D printing technology to generate 3D printed soil samples based on the pore scale information of the original soil. The wettability of several printing materials is examined by measuring contact angles of water droplets on the materials in order to find the material similar to the soil. The 3D sample is printed and the SWCC measurement is performed using a pressure chamber device, and compared to the results of SWCC for the original soil sample.