Effects of Environmental Humidity and Dry-Wet Cycle on Crack Development of Compacted Loess

To investigate the effects of environmental humidity and wet-dry cycles on crack development in compacted loess, an artificial climate chamber was used to simulate natural climatic conditions. Orthogonal experiments were conducted to study crack development in compacted loess under varying environmental humidity and wet-dry cycles. Digital image processing techniques were employed to reveal the evolution patterns of cracks under different environmental humidity and wet-dry cycle conditions. The results indicate that: Under wet-dry cycles, cracks in compacted loess exhibit a distinct phased growth trend, namely the crack initiation stage, rapid growth stage, and stabilization stage. Influenced by changes in dry density, the internal cohesion and the frequency of "impurity points" show significant differences, while the crack development indicators exhibit clear patterns. The total crack length, crack ratio, and fractal dimension all tend to decrease with increasing dry density. Crack evolution is closely related to the evaporation effect of the soil, and humidity changes are directly linked to the evaporation effect. Therefore, humidity variations have a certain impact on the total crack length, crack ratio, average crack width, fractal dimension, and directionality, particularly on the average crack width, where high humidity promotes crack expansion in the width direction. These findings provide a foundation for further research on the service performance of loess high-fill foundations under crack propagation effects and offer references for the design and construction of loess high-fill foundations in practical engineering projects influenced by climatic conditions.