Analysis of Rainfall-Induced Landslide on Unsaturated Soil Slopes

Sangseom Jeong,Junghwan Kim,Kwangwoo Lee,Yongmin Kim

doi:10.3390/su9071280

Sangseom Jeong, Junghwan Kim + Show 2 more

Open Access

https://doi.org/10.3390/su9071280

Copy DOI

Abstract

This paper investigates rainfall-induced landslides on partially saturated soil slopes using the 2011 Umyeonsan landslides at the center of Seoul, Korea. An integrated analysis of rainfall-induced landslide was carried out through laboratory tests, field tests, and numerical analysis. The results of comprehensive investigations in the Umyeonsan region demonstrate that landslide activity is closely related primarily to rainfall and soil properties and slope geometry, and vegetation. Numerical analysis was also performed to confirm the effect of these factors on landslide occurrence. Special attention was given to rainfall penetration analysis to determine the wetting band depth for shallow and deep-seated slope failure in watershed-scale landslide. The simulated results agree closely with the investigation results, which indicates that the applied method is appropriate for use in the simulation of landslides in unsaturated soils.

Highlights

Landslides are common mass-movement processes in mountainous areas, in areas covered by residual soils overlying extensively weathered granite [1,2]
A rigorous numerical method using hydro-geotechnical coupled analysis to determine the wetting band depth for shallow and deep-seated slope failure in watershed-scale landslide was applied to confirm the effect of rainfall and soil properties and slope geometry, and vegetation on landslide occurrence
The overall objective of this study is to investigate the rainfall-induced landslides on partially saturated soil slopes using the 2011 Umyeonsan landslides

Summary

Introduction

Landslides are common mass-movement processes in mountainous areas, in areas covered by residual soils overlying extensively weathered granite [1,2]. When South Korea experienced record rainfall in June and July 2011, some 150 landslides occurred in the Umyeonsan region, affecting 13 villages. These landslides significantly impacted society because the mountain is located in a central part of Seoul, South Korea. Many researchers [2,4,5] have studied rainfall-induced landslides through laboratory and field tests, as well as through numerical analysis They have presented a mechanism for rainfall-induced landslides that commonly occur when the wetting bands progress into the soil, resulting in a loss of suction and a reduction in effective stress [6,7]. According to related studies by Rahardjo et al [8], Ng et al [9,10] and Jeong et al [2], landslides are commonly triggered by external stimuli, including modified slope stability conditions, increasing stress, or reductions in strength

Objectives

Methods

Results

Conclusion