The initiation of rainfall induced landslides is affected by various factors, such as the material properties of soil, topographic features, geological and hydrological characteristics, slope surface cover, and vegetation 3,4. Apr 04, 2018 the discussers argued a fundamental but important topic in slope stability analysis in finiteelement plaxis code. These failures usually occur in regions of the world where steel slopes consisting of residual soils are subjected to periods of prolonged and heavy rainfall. In an effort to predict the timing and location of such landslides, we developed a model of the infiltration process using a two. Dec 16, 2017 physically based approaches for the regional assessment of slope stability using digital elevation model dem topography usually consist of onedimensional 1d descriptions and often include more simplifying assumptions than realistic, threedimensional 3d analyses. This paper aims to investigate the variations in rainfall patterns in singapore and its effect on slope stability. Analysis method for slope stability under rainfall action. T1 development of a gisbased 3d slope stability analysis system for rainfall induced landslide hazard assessment. The slope stability is represented by the factor of safety. Scoops3d evaluates slope stability throughout a digital landscape represented by a digital elevation model dem.
Development of a gisbased 3d slope stability analysis. Pdf many of the raininduced landslides are occurred in unsaturated colluvium soil. Development of a gisbased 3d slope stability analysis system. Using recorded rainfall, measured shear strength parameters and the swrc, and site geology, transient slope stability analyses are conducted to reconstruct the failure events. Trigrs transient rainfall infiltration and gridbased regional slopestability model is a fortran program for computing transient porepressure changes, and attendant changes in the factor of safety, due to rainfall infiltration using the method outlined by iverson 2000. Results of the studies suggest that for a steep hillside slope underlain by a shallow bedrock similar to the. Movement of the wetting front near the slope surface was triggered by rainfall and related to rainfall intensity and duration, which is consistent with the numerical solution. Rainfall induced landslides have caused many human casualties and severe property damage worldwide 1,2. This study present the relationship between rainfall and suction of soil which induced the slope instability and the slope stability analysis involving a building which may cause by instability due to suction variation. In the context of constructing early warning systems in regions where extensive data on landslide occurrences and associated.
Apr 10, 2015 scoops3d evaluates slope stability throughout a digital landscape represented by a digital elevation model dem. N2 the assessment of landslide hazard should give answers to three key questions. The influence of surface runoff to 3d slope stability. Rainfall induced landslides are common around the world. Moisture content, porewater pressure, and slope deformation were monitored to quantify the relationship between rainfall infiltration and loess slope stability. Effects of twophase flow of water and air on shallow.
Paper open access rainfall induced slope failure detection. Previous studies assess them mostly from the perspective of a single discipline. The program computes transient porepressure changes, and attendant changes in the factor of safety, due to rainfall infiltration. This paper seeks to address this problem by adding the rainfall factor as input to\ud hovland 3d slope stability analysis in the form of pore water pressure. The early warning based on realtime prediction of rain induced instability of natural residual slopes helps to minimise human casualties due to such slope failures. After attending slope stability and landslides, you will understand. In this article, based on the above 1 and 2, the authors focus on the two types of infiltration pattern saturated and unsaturated, the two types of failure modes sallow and deepseated failure and. A possible disastrous consequence of this change is the occurrence of rainfall induced slope failures. Slope stability analyses are mostly conducted by identifying or assuming a potential failure surface and assessing the factor of safety fs of that surface. The effect of antecedent rainfall on slope stability.
Rainfall is a major trigger of shallow slope failures, and it is necessary to consider the spatial correlation of soil properties for probabilistic analysis of slope stability in heterogeneous soil. Learn from expert and diverse course faculty about industryleading and advancing topics such as rainfall induced movements, slope risk assessment and asset management, and lidar and photogrammetry. Slope failures are caused by not only the infiltration of water. It covers theoretical models of rainfall infiltration and stability analysis, reliability analysis based on coupled hydro. In this study, a case study of a weathered soil slope in korea was performed to identify the rainfall induced landslides considering the spatial variability of the soil properties and the. Each year, rain induced slope failures cause significant damages in highway infrastructures and environments, as well as tragic losses of human lives around the world. This study examined the mechanism causing the slope failure. Laboratory characterization of rainfallinduced loess. The initiation of rainfallinduced landslides is a ected by various factors, such as. Stability analysis of rainfallinduced slope failure. Rainfallinduced landslides in steep soil slopes of volcanic origin are a major threat to human lives and infrastructure.
Rainfall induced slope failure is produced by an increase in porewater pressure, a rise in unit weight of the soil mass, and hydrodynamic forces during or shortly after a period of intense. Trigrs a fortran program for transient rainfall infiltration and gridbased regional slopestability analysis, version 2. A transient seepage and slope stability analyses were carried out for a case of rainfall induced landslide in air laya indonesia. Evaluate the probability of failure in rainfallinduced. The initiation of rainfallinduced landslides is affected by various factors, such as the material properties of soil, topographic features, geological and hydrological characteristics, slope surface cover, and vegetation 3,4.
In both studies the deterministic model used is an uncoupled seepage analysis program seepw geoslope ltd, 2001a and a companion slope stability analysis program. Probabilistic analysis of weathered soil slope in south korea. Introduction rainfallinduced landslides have caused many human casualties and severe property damage worldwide 1,2. Effect of rainfall on stability of unsaturated earth. Tung and chan 2003 performed probabilistic analyses of rainfall infiltration and slope stability considering uncertainties in swccs by the latin hypercube sampling technique.
Rainfallinduced slope failure is a common problem in areas with slope constructed on high plasticity clays. During the infiltration process, the matric suction in the unsaturated soil slope decreases as the saturation increases with time, thereby reducing the shear strength of the. This approach of assigning a single fs to a potentially unstable slope provides little insight on where the failure initiates or the ultimate geometry and location of a landslide rupture surface. Feb 26, 2018 the transient rainfall infiltration and gridbased regional slope stability model trigrs is a fortran program designed for modeling the timing and distribution of shallow, rainfall induced landslides. Geohazard potential of rainfall induced slope failure on. Rainfallinduced landslides have caused many human casualties and severe property damage worldwide 1,2. The graphics and the pointandclick data input are also very good and makes the program very easy to use. A possible disastrous consequence of this change is the occurrence of rainfallinduced slope failures. Effect of variations in rainfall intensity on slope. Trigrs transient rainfall infiltration and gridbased regional slope stability model is a fortran program for computing transient porepressure changes, and attendant changes in the factor of safety, due to rainfall infiltration using the method outlined by iverson 2000. One of the important role in slope stability is matric suction. Infiltration of rain water results in reduction in soil matric suction and shear strength, which eventually leads to reduction in slope stability. The discussers argued that, for numerical modeling of a rainfallinduced shallow landslide problem, the drained condition should be prescribed because excess porewater pressure within the soil slope could be fully dissipated.
The influence of surface runoff to 3d slope stability analysis for rainfall induced landslide noraidah keling1, izham mohamad yusoff2, habibah lateh3 4and uznir ujang 1,2,3 school of distance education, universiti sains malaysia 4 department of geoinformatics, universiti teknologi malaysia, johor bahru. Slope stability studies in different parts of the world have indicated that infiltration of rain water into the soil has an adverse effect on the stability of earth slopes. We investigated a new application of the wellknown, publicly available software trigrs transient rainfall infiltration. The landslide occurred in december 2002 on a dumping area of an open coal mining site. Analysis of rainfallinduced slope instability using a. Traditional slope stability analysis mostly adopts the limit equilibrium method, which predetermines the slope failure surface and assumes that failure occurs simultaneously at all points of the failure surface. We used rainfall intensities of 45 and 70 mmh table 2. We have extended iversons 2000 method by implementing. Threedimensional, timedependent modeling of rainfall. Real time prediction of rainfall induced instability of. Learn from expert and diverse course faculty about industryleading and advancing topics such as rainfallinduced movements, slope risk assessment and asset management, and lidar and photogrammetry. Slopew can effectively analyze both simple and complex problems for a variety of slip surface shapes, porewater pressure conditions, soil properties, and loading conditions.
In both studies the deterministic model used is an uncoupled seepage analysis program seepw geo slope ltd, 2001a and a companion slope stability analysis program. One aspect of climate change is the variations in rainfall patterns, which affect the flux boundary condition across ground surface. This is a parallel implementation of trigrs, the transient rainfall infiltration and gridbased regional slope stability model for the timing and distribution of rainfall induced shallow landslides. The program uses a threedimensional 3d method of columns limitequilibrium analysis to assess the stability of many potential landslides typically millions within a. This investigation has been carried out to determine rainfall induced landslide at chakkargaon of port blair. Ge, principal consultant with gregory geotechnical gregeo.
Details of the location, size and morphology of the landslides are presented. Effect of rainfall pattern on slope stability 1abu talib mohd khaidir, 2kasa anuar, 1noriyuki yasufuku, 1hazarika hemanta, 1ryohei ishikura 1department of civil engineering, kyushu university 2department of civil engineering, universiti kebangsaan malaysia 1. The disturbed zone in the permanent cut slopes induced by excavation is therefore one of the most important aspects in slope stability and deformation evaluation. Closure to influence factors involving rainfallinduced. The software in general is very good and ties in well with the way we do things here. This paper seeks to address this problem by adding the rainfall factor as input to\ud hovland 3d slope stability analysis in. The transient rainfall infiltration and gridbased regional slopestability model trigrs is a fortran program designed for modeling the timing and distribution of shallow, rainfallinduced landslides.
The discussers argued a fundamental but important topic in slope stability analysis in finiteelement plaxis code. Rainfallinduced slope failure is produced by an increase in porewater pressure, a rise in unit weight of the soil mass, and hydrodynamic forces during or shortly after a period of intense. Effects of twophase flow of water and air on shallow slope. For regions with tropical climate like malaysia,\ud the study of rainfall induced landslide is crucial due to the many landslide incidents triggered by\ud heavy rainfall. Slopestability analyses are mostly conducted by identifying or assuming a potential failure surface and assessing the factor of safety fs of that surface. Paper open access rainfall induced residual soil slope. The method is based on the balance of forces and torques. Slope stability analysis under unsaturated conditions. Effect of variations in rainfall intensity on slope stability.
T1 development of a gisbased 3d slope stability analysis system for rainfallinduced landslide hazard assessment. Intoduction many studies have indicated that the infiltration of rainwater into a slope decreases the stability of the slope. Suryo, eko andi 20 real time prediction of rainfall induced instability of residual soil slopes associated with deep cracks. This is a parallel implementation of trigrs, the transient rainfall infiltration and gridbased regional slopestability model for the timing and distribution of. Continuum deformation and stability analyses of a steep. Trigrsa fortran program for transient rainfall infiltration. Laboratory characterization of rainfallinduced loess slope. If step1 analysis shows critical stability for the forthcoming year, it is recommended that step2 be used for more accurate warning against the future failure of. Rainfall induced slope failure is a common geotechnical hazard in many parts of the world. With global climate change, their frequency is increasing and the consequences are becoming greater. Stability of these slopes is high during dry periods due to the. In this study, a case study of a weathered soil slope in korea was performed to identify the rainfallinduced landslides considering the spatial variability of the soil properties and the.
Transient seepage and slope stability analysis for. Case studies of rainfallinduced failure of cut slopes seboong oh a. Analysis of rainfallinduced slope instability using a field. The aim of this paper was to examine the effect of spatial variability of hydraulic conductivity, commonly existing in nature, on rainfallinduced failures of residual soil slopes. Asianpacific aquaculture 2019 chennai, india meeting. Stability analysis and probabilistic assessment integrates probabilistic approaches with the geotechnical modeling of slope failures under rainfall conditions with unsaturated soil. Rainfallinduced landslides are common around the world. Slope stability analysis slopew is the leading slope stability software for soil and rock slopes. Field investigation and numerical study of a siltstone slope. The aim of this paper was to examine the effect of spatial variability of hydraulic conductivity, commonly existing in nature, on rainfall induced failures of residual soil slopes. Seepage and slope stability modelling of rainfallinduced. Field investigation and numerical study of a siltstone. A case study is presented in order to identify the effect of antecedent rainfall on slope stability for singapore.
These are the common methods used in the slope stability software and the. The lowest factor of safety obtained after repeated analysis. Stability analysis and probabilistic assessment by lulu zhang and jinhui li english 2016 isbn. We investigated a new application of the wellknown, publicly available software trigrs transient rainfall infiltration and. Analysis of rainfallinduced slope instability using a field of local factor of safety ning lu,1 basak senerkaya,1 alexandra wayllace,1 and jonathan w. The elevation model of the area is prepared using surfer software. Therefore, landslide triggered by rainfall is a complicated process. Parametric study was carried out at typically residual soil slopes with two distinctively different types of hydraulic conductivity, high ks104 ms and low ks. Transient rainfall induced and gridbased regional slopestability model trigrs model baum et al.
In this calculation, rainfall is predicted for the next hour or 24 hours and the stability of the slope is calculated one hour or 24 hours in advance using real time rainfall data. A storm in february 1995 during which 95 mm of rain fell in 2 \\frac12\ h caused more than twenty shallow landslides on the nanyang technological university campus. It covers theoretical models of rainfall infiltration and stability analysis, reliability analysis based on coupled hydromechanical modelling, stability of slopes with cracks, gravels and spatial heterogenous soils, and probabilistic model calibration based on measurement. This includes the slope stability equation of fellenius 8,9, simplified bishop method 2, morgenstern and price 23, spencers method 27,28 and sharma method 25. Slope stability and landslides engineering professional. Physically based approaches for the regional assessment of slope stability using digital elevation model dem topography usually consist of onedimensional 1d descriptions and often include more simplifying assumptions than realistic, threedimensional 3d analyses. Deformation was monitored using a 3d laser scanner leica scanstation 2. In this article, based on the above 1 and 2, the authors focus on the two types of infiltration pattern saturated and unsaturated, the two types. Hydrologic response 29 here we use a 30 slope composed of homogeneous silty soil as an example to illustrate the effects of rainfall. Rainfallinduced failures of residual soil slopes with. Seepage and slope stability modelling of rainfallinduced slope failures in topographic hollows kiran prasad acharyayz, netra prakash bhandaryx, ranjan kumar dahal and ryuichi yatabej ygraduate school of science and engineering, ehime university, 3 bunkyocho, matsuyama 7908577, japan.
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