Effects of water immersion on the mechanical properties and hydrochemical characteristics of cemented calcareous soil

The mechanical response of cemented calcareous soils to water immersion is critically influenced by the complex architecture of their particulate framework and cementing materials. Understanding the mechanical and hydrochemical properties of these soils under saturated conditions is crucial for assessing the stability of geoengineering structures. The research detailed in this manuscript evaluates the influences of water immersion on the mechanical and hydrochemical characteristics of cemented calcareous soil collected near the Jinsha River. Additionally, the study discusses the implications of these soil properties for geological phenomena located in proximity to the sampling area. The results showed that prolonged immersion precipitates substantial alterations in the hydraulic conductivity of cemented calcareous soil, accompanied by extensive ion dissolution that modifies its hydrochemical properties. The soaking solution exhibits alkalinity with high concentrations of Ca²⁺ and HCO₃⁻. Initial short-term immersion augments the strength of cemented calcareous soil, while a progressive decline in strength occurs as the immersion period extends, with the natural state displaying markedly greater strength relative to the dried state. Long-term immersion facilitates the moisture infiltration into the interstitial spaces between particles, dissolving the cementing material and undermining the interparticle bonds, which critically impairs the mechanical properties and stability of the soil. Furthermore, localized seepage facilitates the migration and precipitation of soluble salts in moisture-prone environments, exacerbating the weathering and degradation processes. Such long-term immersion results in structural transformations within the soil, undermining the cementation structure and potentially precipitating soil collapse.