Abstract Infiltration is of great concern in many fields like hydrology, agriculture as well as geotechnical and geological engineering. This study aims to investigate water infiltration in a cracked soil. Infiltration tests were conducted on compacted soil samples with different cracking degrees by drying to various water contents. Three drying-wetting cycles were applied. Experimental results show that no desiccation cracks are observed in the first drying process while cracks initiate and propagate in the second and third drying processes. Different from the infiltration curve of the non-cracked soil sample consisting of two distinct stages, that of the cracked soil consists of three distinct stages, representing constant, rapid reduction and gradual reduction in infiltration rate, respectively. A modified equation is proposed to describe the infiltration behavior of a cracked soil considering the prehealing time of cracks. Furthermore, it is found that for the tested soil, 4% of surface crack ratio is a critical value. When surface crack ratio is smaller than the critical value, its influence on infiltration capacity is insignificant. Afterwards, the infiltration capacity increases dramatically with increasing surface crack ratio. Based on this observation, a piecewise function is proposed to characterize the relationship between the normalized infiltration capacity of cracked soil and surface crack ratio. Infiltration capacity also increases with decreasing initial water content and increasing number of drying-wetting cycles. In terms of steady final infiltration rate, it increases with increasing initial water content as well as increasing number of drying-wetting cycles, but is not affected by desiccation cracking.

中文翻译：

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考虑干湿循环影响的裂隙土壤中的水分入渗

摘要 入渗在水文、农业以及岩土和地质工程等许多领域都受到广泛关注。本研究旨在研究开裂土壤中的水渗透。通过干燥至不同含水量，对不同开裂程度的压实土样进行入渗试验。应用了三个干湿循环。实验结果表明，在第一次干燥过程中没有观察到干燥裂纹，而裂纹在第二次和第三次干燥过程中开始并扩展。与非开裂土样由两个不同阶段组成的入渗曲线不同，开裂土由三个不同阶段组成，分别代表入渗速率恒定、快速降低和逐渐降低。提出了一个修正方程来描述考虑裂缝预愈合时间的裂缝土壤的入渗行为。此外，发现对于被测土壤，4%的表面裂纹率是一个临界值。当表面裂纹率小于临界值时，其对渗透能力的影响不显着。之后，渗透能力随着表面裂纹率的增加而急剧增加。基于这一观察，提出了分段函数来表征裂隙土的归一化入渗能力与地表裂隙率之间的关系。渗透能力也随着初始含水量的降低和干湿循环次数的增加而增加。在稳定的最终渗透率方面，