Seasonally Frozen Soil Characteristics and Feasibility Study of Turf Slope Protection

Abstract

Seasonally frozen soil regions are susceptible to temperature fluctuations and atmospheric precipitation, which can lead to frost heave and thaw settlement. This phenomenon is particularly prominent in road-cut slope areas, where freeze‒thaw cycles play a crucial role in slope instability. Consequently, a study of a road graben slope in Aba, Sichuan Province, was carried out. This study involved unit tests and a series of model experiments to examine the frost heave characteristics and investigate the feasibility of implementing turf slope protection measures for road-cut slopes in seasonally frozen soil regions. The results indicate that the soil in the studied region exhibits pronounced freezing characteristics, necessitating the implementation of frost heave prevention measures. Turf slope protection can reduce the frost swelling rate of soil, improve the shear strength, cohesion, and internal friction angle of soil, and inhibit the weakening of shear strength and cohesion strength under freeze‒thaw cycles; the more freeze‒thaw cycles there are, the more obvious the inhibiting effect. Regarding the weakening effect on the shear strength and cohesive strength of turf soil samples and pure soil samples, we proposed an exponential model to describe the degree of weakening, which is mainly related to the number of freeze‒thaw cycles. The results of the study demonstrate the feasibility of turf slope protection, providing valuable technical insights for the protection of road graben slopes in seasonally frozen soil areas.

Keywords: Seasonally frozen soil, Road graben slopes, Freeze‒thaw cycles, Turf slope protection