Experimental Study on the Dynamic Evolution Characteristics of Desiccation Cracking of Fiber-Improved Fine-Grained Coral Soil

Abstract

This study was aimed at exploring the dynamic evolution characteristics of desiccation cracking in fiber-improved fine-grained coral soil, with a focus on the effects of layer thickness and polyvinyl alcohol (PVA) fiber (vinylon staple fibers) content. Through desiccation cracking tests and image processing technology, the evaporative water-loss characteristics, change in crack parameters, fractal dimension, crack propagation velocities, and morphological distribution of the fine-grained coral soil were obtained. The dynamic evolution law of cracks under the coupling effect of layer thickness and fiber content was acquired. The multiscale characteristics of soil macroscopic, mesoscopic, and microscopic cracks were determined. The PVA fibers exhibited good adhesion to the soil particles and played a bridging role in the multiscale cracks in the fine-grained coral soil. However, the presence of the fibers also led to the generation of finer microscopic cracks. In addition, the crack evolution mechanism and cracking criterion in fine-grained coral soil under the coupling effect of PVA fiber and layer thickness were elucidated. The results are highly significant for the potential development and optimal utilization of fine-grained coral soils in the near future.