Laboratory tests involving soil desiccation cracking are subjected to geometrical boundary constraints that are not always present in field conditions. To better understand the effects of sample geometry on desiccation cracks, several researchers have used controlled climatic conditions coupled with image analysis to accurately quantify the crack characteristics of soil samples subjected to laboratory studies. However, to date, no known studies in the literature present a simple method for determining the appropriate sample size for laboratory desiccation cracking testing that ensures the effects of boundary conditions are minimized. The primary objective of this research is to address this gap by proposing an experimental approach to determine a representative elementary area (REA) for soil desiccation cracking studies in the laboratory. To achieve this, we conducted four series of tests using an environmental chamber. One preliminary test series was carried out to identify the optimal sample preparation and REA testing techniques. Subsequently, three additional series of REA tests were conducted with sample thicknesses of 2.5, 5.0, and 7.5 mm to explore the impact of sample size on the REA. The REA for each sample thickness was determined by examining the surface area at which the surface crack ratio (RSC) for the sample was unaffected by boundary constraints. The results indicate that as sample thickness increases, REA increases. Further research is needed to determine how the REA is affected by sample shape and soil type.

中文翻译：

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确定土壤干燥开裂的代表性基本区域


涉及土壤干燥开裂的实验室测试受到几何边界约束的影响，而这些约束在现场条件下并不总是存在。为了更好地了解样品几何形状对干燥裂纹的影响，一些研究人员使用受控气候条件和图像分析来准确量化接受实验室研究的土壤样品的裂纹特征。然而，迄今为止，文献中没有已知的研究提供一种简单的方法来确定实验室干燥开裂测试的合适样品量，以确保边界条件的影响最小化。本研究的主要目的是通过提出一种实验方法来解决这一差距，以确定实验室土壤干燥开裂研究的代表性基本区域 （REA）。为此，我们使用环境室进行了四个系列的测试。进行了一项初步测试系列，以确定最佳样品制备和 REA 测试技术。随后，对 2.5、5.0 和 7.5 mm 的样品厚度进行了另外三个系列的 REA 测试，以探索样品量对 REA 的影响。通过检查样品的表面裂纹率 （RSC） 不受边界约束影响的表面积来确定每个样品厚度的 REA。结果表明，随着样品厚度的增加，REA 会增加。需要进一步的研究来确定 REA 如何受样品形状和土壤类型的影响。