Water-holding characteristics of loess in Xingyang

Loess is a water-sensitive soil whose hydraulic behavior strongly influences its engineering performance. This study investigates the soil-water characteristic curves (SWCC) and water-holding behavior of undisturbed and remolded Q 3 loess from Xingyang under different dry densities based on pressure membrane tests. In addition, the pore structure characteristics of the loess were analyzed qualitatively and quantitatively through scanning electron microscopy. The results indicate that the SWCC of Xingyang loess can be divided into three stages: initial, transition, and residual stages. The undisturbed loess exhibits a steep decline in water content at low matric suction, reflecting rapid drainage and a relatively weak water-holding capacity. With decreasing dry density, the rate of water loss during the transition stage increases, while differences among samples gradually diminish in the residual stage. Microstructural analysis reveals that undisturbed loess is dominated by large and medium pores, whereas remolding and compaction transform the pore system toward medium and small pores, resulting in a denser and more uniform structure and enhanced overall water-holding capacity. Compared with typical loess from the Loess Plateau, Xingyang loess is characterized by high porosity, low dry density, and relatively weak water retention, which can be significantly improved through remolding and compaction.