Evaluation of slope stability with topography and slope stability analysis method

Abstract

In existing researches connected with landslide, natural slope was regard as a parallel slope, but it was found that many landslides were occurred on the concave and convex slopes besides parallel slopes. This study was performed to evaluate the effect of shape and length of slope and soil depth for slope stability analysis and to compare infinite slope analysis with circular failure analysis for grid by grid analysis in prediction of GIS-based landslide hazard. As grid size is increased, average slope and curvature were decreased and the decreasing tendency was prominent in mountainous areas. Comparing infinite slope analysis and circular failure analysis for various degree of slope and soil depth, safety factor by infinite slope analysis is larger than that by circular failure analysis. Result showed that the factor safety depends on the shape of slope which is composed of two continuous slopes, if grid size is small (such as 5 m×5 m). So after due consideration for soil depth and topography, proper slope stability analysis must be performed.

Numerical analysis on influence of principal parameters of topography on hillslope instability in a small catchment

“…For example, the factor of safety Fig. 9a, b are consistent with those of some recent studies, such as Gofar et al (2009), Cha andKim (2011) and Zhan et al (2013).…”

“…Therefore, topography is a major controlling factor of all kinds of hillslope instability problems. A topographical unit consists of slope inclination, slope shape, slope length, slope width, and soil depth (Dietrich et al 1987(Dietrich et al , 2008Iida 1999;Talebi et al 2008;Cha and Kim 2011), and therefore these can be considered as topographic parameters.…”

“…However, in these studies, only slope inclination has been reported as an important parameter from the perspective of slope stability. Some theoretical studies (e.g., Griffiths et al 2011;Cha and Kim 2011) have investigated the influence of slope inclination and soil depth on stability analysis of infinite slopes. The deficits in these studies are: (1) infinite slope analysis is not sufficient to completely represent the real conditions of hillslopes, and (2) slope transient porewater pressure behavior in response to rainfall and its influence on hillslope instability cannot be understood from these studies.…”

Identifying areas susceptible to high risk of riverbank collapse along the Lower River Murray

“…Generally, the factors that may affect the stability of the riverbanks can be classified into two different groups: natural and artificial [2]. Natural factors include site topography, bank and riverbed stratigraphy, soil and rock properties, river level fluctuation and climatic factors which include precipitation and evaporation [3]. In the case of the Lower River Murray, more than 162 riverbank collapse-related incidents were reported between 2005 and 2010 and the collapses were identified as dominantly triggered by unprecedented low river levels [1,[4][5][6].…”

“…More specifically, the subjective method is based mainly on field experience; while both the WLC and QMC models of the objective method generate the composite and numeric maps by overlaying the various causal factor layers such as geology, hydrology, topography and geomorphology [10,11]. As the most important parameter for evaluation of slope instabilities [3], topography is considered as an indicator of past failures and potential future instability [2]. Vanacker et al [12] believed that the prediction of slope failure is usually based solely upon topographical attributes.…”