Effect of Freeze-Thaw Cycles on Soil Detachment Capacities of Three Loamy Soils on the Loess Plateau of China

Abstract

Soil detachment is the initial phase of soil erosion and is of great significance to study in seasonal freeze-thaw regions. In order to elucidate the effects mechanism of freeze-thaw cycles on soil detachment capacity of different soils, a sandy loam, a silt loam, and a clay loam were subjected to 0, 1, 5, 10, 15, and 20 freeze-thaw cycles before they were scoured. The results revealed that with increased freeze-thaw cycles, soil bulk density and water-stable aggregates content decreased after the first few times and then kept nearly stable after about 10 cycles, especially for sandy loam. The shear strength of all soils gradually decreased as freeze-thaw cycles increased, except the values of clay loam increased subsequent to the 5th and 15th cycles. After the 20th cycle, the degree of decline of silt loam was the greatest (77.72%), followed by sandy loam (63.18%) and clay loam (39.77%). The soil organic matter of clay loam was much greater than silt loam and sandy loam and all significantly increased after freeze-thaw. Soil detachment capacity of silt loam and sandy loam was positively correlated with freeze-thaw cycle, which was contrary to findings for clay loam. The values of clay loam increased at first and then decreased during the cycles, reaching minimum values at about the 15–20th cycle. After the 20th cycle, the values of sandy loam and silt loam significantly increased 1.62 and 4.74 times over unfrozen, respectively, which was greater than clay loam (0.53 times). A nonlinear regression analysis indicated that the soil detachment capacity of silt loam could be estimated well by soil properties (R2 = 0.87, p < 0.05). This study can provide references for the study of the soil erosion mechanism in seasonal freeze-thaw regions.

Unraveling the Mystery of Water-Induced Loess Disintegration: A Comprehensive Review of Experimental Research

“…Most of the loess area is located in arid and semi-arid regions, with significant freezethaw cycles due to temperatures fluctuating around 0 • C. Freeze-thaw erosion, a common type of soil erosion, occurs frequently in the Loess Plateau region [57][58][59]. The microstructure and mechanical strength of loess will be affected by freeze-thaw action [57,[60][61][62], and the disintegration of loess is closely related to the microstructure and mechanical strength of soil. Therefore, the freeze-thaw cycle is one of the important water environment factors affecting the disintegration of loess.…”

Soil Water Erosion

“…Lu et al [13] went further than Su et al [10] by investigating the effects of freeze-thaw cycling on the soil detachment capacities of three loamy soils on the Loess Plateau of China. After 20 freeze-thaw cycles, the degree of decline of silt loam was the greatest (77.72%), while sandy loam (63.18%) and clay loam (39.77%) showed smaller degrees of decline.…”

Effects of Cyclic Freezing–Thawing on Dynamic Properties of Loess Reinforced with Polypropylene Fiber and Fly Ash

“…Loess is widespread soil that stretches from seasonal frozen areas to permafrost areas in Northern China. Due to a lack of coarse-grained materials, it is often selected as a filling material for highways, railways, and high-speed railways (HSR) despite its unfavorable engineering characteristics such as its large pores and high sensitivity to water and temperature [1][2][3]. An effective method to mitigate these deficiencies and to improve the fill is to reinforce the soil with cementitious additives and reinforcing materials [4].…”