Effects of sliding liquefaction on homogeneous loess landslides in western China

Abstract

Sliding liquefaction is considered to be the cause of high-speed and long-distance sliding of some homogeneous loess landslides in western China. However, there is still a lack of necessary experimental research and analysis on the effects of sliding liquefaction on these landslides. In this work, the effects of sliding liquefaction on irrigation-induced, high-speed and long-distance loess landslides on the South Jingyang Tableland area in China are studied by performing large-scale ring shear tests and using the sled mode. The results are as follows. (1) There are two kinds of long-runout sliding modes of loess landslides on the South Jingyang Tableland: sliding along the terrace surface and sliding within the saturated terrace alluvium, which is associated with sliding liquefaction. Both sliding modes can lead to long-runout sliding. (2) There are some differences in the inclination of the sliding surface between the two sliding modes. Based on the inclination of the sliding surface, the corresponding sliding mode can be distinguished. (3) Under the two sliding modes, the large shear mechanical properties of the two-layer soil composed of loess and alluvial sandy silt show significant differences. The friction between the loess and dry terrace alluvium increases with increasing normal stress and shear rate, while the friction between the loess and saturated terrace alluvium presents the opposite trend. The results show that the sliding distances under different sliding modes present opposite trends with the change in sliding speed. (4) Based on the test results from the ring shear tests and the morphological characteristics of the sliding surface, the sliding mode and sliding distance of a loess landslide can be identified and predicted.

Determining the failure mechanism and analyzing numerical stability of a Loess slope in seismic zones: a case study

“…Also, Hong et al, (2021) based on their studies suggested that liquefaction could be the cause of some rapid landslides and great displacement in uniform loess slopes. Based on the eld survey and examination of a landslide that occurred in a village in the Xiangning Province of China in 2019, Shi et al, (2020) showed that the penetration of surface water into weak layers in the depth of the slope reduced the shear strength of loess and led to a failure.…”

Flowslide High Fluidity Induced by Shear Thinning

“…However, most of the experiments are conducted under free‐surface or low‐normal‐stress conditions, in which the stress state is far from a real scale. Annular shear tests (Bagnold, 1954) and ring‐shear tests (Hong et al., 2021; Iverson et al., 1997) are also used to study the rheologies of solid‐fluid mixtures in a more controlled condition. Viscosity, which is the variation of shear resistance $$\tau $$ with shear strain rate $$\dot{\gamma }$$, well describes the fluidity of granular flows (Hungr, 1995; Jeong et al., 2010; Wang et al., 2021).…”