Landslide Failure Mechanisms of Dispersive Soil Slopes in Seasonally Frozen Regions

Lixiang Wang,Miao Wang,Xiaoming Yuan,Hui Yao

doi:10.1155/2020/8832933

Abstract

Hydraulic projects with dispersive soil in seasonally frozen regions are susceptible to landslide failures. The mechanism of such landslide failures has not been fully understood thus far; therefore, it was investigated in this study by using on-site surveys, laboratory tests, and theoretical calculations. The results showed that the landslides of dispersive soil in seasonally frozen regions could be categorized as shallow-seated landslides and deep-seated landslides. The preconditions for landslide occurrence were soil mass looseness and cracks, caused by freeze-thawing. The degradation of dispersive soil led to a rapid influx of water into the soil. The reason for shallow-seated landslides was that the numerous sodium ions present in the soil mass dissolved in water and damaged the soil structure, resulting in a substantial reduction in shear strength. The reason for deep-seated landslides, however, was the erosion due to rainfall infiltration after the shallow-seated landslides caused tensile cracks at the top of the slope, leading to soil instability. Landslide failures occurred when the dispersing soil slope underwent freeze-thawing and saturated soaking. The sliding surface was initiated at the top of the slope and gradually progressed to the bottom along the interface between the soil layers.

Highlights

Dispersive soil is widely distributed across the world. e United States, Spain, Australia, South Africa, Iran, and China have numerous water conservancy and road construction projects based on dispersive soil [1,2,3,4,5]
Erosion damage is widespread around the world, among which large areas of gullies appear in the Northeast Plain of China and the Australian grasslands
We discovered a large area of dispersive soil slope landslide damage at the survey project site. e occurrence of a landslide on such a low-height slope was extremely unusual

Summary

Introduction

Dispersive soil is widely distributed across the world. e United States, Spain, Australia, South Africa, Iran, and China have numerous water conservancy and road construction projects based on dispersive soil [1,2,3,4,5]. E United States, Spain, Australia, South Africa, Iran, and China have numerous water conservancy and road construction projects based on dispersive soil [1,2,3,4,5]. E common damage in dispersive soil projects includes erosion damage, seepage piping damage, frost heave damage, and landslide damage. Seepage piping damage mainly occurs on the side of the dam body of a dispersive soil dam and the shoulder of a road subgrade. E frost heave damage of dispersive soil mainly occurs at the locations of buildings and channel slopes in Alpine regions, such as the northern United States, the Calgary region of Canada, southern Australia, and northeastern China. Dispersive soil landslide damage mainly occurs in the position of the channel slope

Methods

Results

Conclusion