Experiments to simulate the salinisation process of loess under a dynamic water cycle

Addressing loess salinisation is a crucial element in preserving ecological stability and fostering sustainable development in the northwest Loess Plateau. To investigate the impacts of salt solution on the properties of loess, independently designed salt solution-loess dynamic cyclic erosion equipment was used to soak the loess. Then, numerous tests were performed to analyse the variability of the effects of salt solution concentrations (SSC) and type, as well as the duration of soaking time, on these physico-mechanical properties. The results demonstrated that after being soaked in two different types of salt solutions for 3 days, the shear strength index of loess preliminary decreased and then increased. The compressibility preliminary increased and then declined when the SSC increased. After a 7-day soaking period, the cohesion of the loess did not change considerably, whereas the internal friction angle increased in proportion to the SSC. The compression of loess tended to initially decrease, subsequently increase, and eventually decrease. Loess can be slowed down in its disintegration process by salt solution, and disintegration duration can be effectively shortened with a prolonged soaking time. Finally, it is examined the evolutionary process of the impact of salt solution on loess microstructure. Moreover, the exchange of clay minerals with iron and aluminium ions is proposed to be the key element determining the water-loess chemical interaction. This study may function as an insightful guide for preventing and treating salinised loess on the Loess Plateau of Northwest China, while also serving as a reference for similar areas worldwide.