The desiccation cracking of soil occurs when shrinkage is restricted during the drying process and the induced tensile stress equals the tensile strength. Thus far, experimental estimations of the tensile stress of soil have not been realized, although such estimates are important for predicting crack initiation. This study presents the development of a laboratory-based desiccation stress test to measure the tensile stress generated during the drying process until crack initiation. In this proposed desiccation stress test, the tensile stress is induced during the drying process in the longitudinal direction of bar-shaped specimens with fixed ends. Desiccation stress tests were performed on sandy soil with a rich fine fraction, and the results were verified through photographic observations of crack initiation and comparisons with the results of direct tension tests. The results show that the desiccation stress test yields reliable tensile stress until cracking. The application of the desiccation test results is illustrated via the verification of an existing model of crack initiation by desiccation. The results of the desiccation stress tests are useful for determining the model parameters that significantly influence the development of tensile stress and enable its accurate prediction until crack initiation.

当干燥过程中收缩受到限制并且诱导拉应力等于抗拉强度时，就会发生土壤干裂。到目前为止，还没有实现对土壤拉伸应力的实验估计，尽管这种估计对于预测裂纹萌生很重要。本研究介绍了基于实验室的干燥应力测试的发展，以测量在干燥过程中产生的拉伸应力，直至裂纹萌生。在这个建议的干燥应力测试中，拉伸应力是在干燥过程中在两端固定的棒状试样的纵向上引起的。对细粒含量丰富的砂质土壤进行干燥应力试验，并通过裂纹萌生的照片观察以及与直接拉伸试验结果的比较来验证结果。结果表明，干燥应力测试产生可靠的拉伸应力直至开裂。通过对现有的干燥裂纹萌生模型的验证，说明了干燥测试结果的应用。干燥应力测试的结果可用于确定显着影响拉伸应力发展的模型参数，并使其准确预测直至裂纹萌生。