Study on hydrothermal migration and interface cracking mechanisms of supporting reinforcing bodies in the root erosion zones of rammed earth sites in arid regions

Abstract

The characteristics of hydrothermal migration and strain variations manifest differently in soils with contrasting properties. The primary objective of this study is to investigate the patterns of hydrothermal transfer and strain changes between the root erosion zone of rammed earth sites and the supporting reinforcing body during the process of desiccation, which leads to the differentiation and cracking of the interface between the reinforcing body and the site itself. This paper presents experimental monitoring conducted on-site regarding temperature, moisture content, strain, and the development of interface cracks in the supporting reinforcing body (including rammed earth repair body, cushion layers, and the site itself) during the drying process. The results indicate that the variations in temperature field, moisture field, and shrinkage strain field during the desiccation of the reinforcing body are distinct, with changes in moisture content predominantly influencing the shrinkage strain of the reinforced soil. Notably, the shrinkage of the reinforcing soil exhibits significant location and directional variability. The suction pressure of the site is a critical factor that leads to the rapid loss of moisture at the interface, as well as changes in the moisture distribution of the reinforcing body; the differential shrinkage between the site material and the reinforcing soil in the interface region is the fundamental reason for the development and propagation of interface cracks.