• Proceedings of the Korean Geotechical Society Conference
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• 1997.09a
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• pp.3-20
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• 1997

• Journal of the Korean Geosynthetics Society
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• v.12 no.2
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• pp.67-74
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• 2013

In this study, the prediction of slope hazard probability was performed to the study area located in Hadae-ri, Woochun-myeon, Hoengsung-gun, Gangwon Province around Youngdong express way using the computer program SHAPP ver 1.0 developed by a decision tree model. The soil samples were collected at total 10 points, and soil tests were performed to measure soil properties. The thematic maps of soil properties such as coefficient of permeability and void ratio were made on the basis of soil test results. The slope angle analysis of topography was performed using a digital map. As the prediction result of slope hazard probability, 2,120 cells among total 27,776 cells were predicted to be in the event of slope hazards. Therefore, the predicted area of occurring slope hazards may be $53,000m^2$ because the analyzed cell size was $5m{\times}5m$.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.5
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• pp.101-108
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• 2017

Recently, the occurrence of landslides has been increasing over the years due to the extreme weather event. Developments of landslides monitoring technology that reduce damage caused by landslide are urgently needed. Therefore, in this study, a strain ratio sensor was developed to predict the ground behavior during the slope failure, and the change in surface ground displacement was observed as slope failed on the field model experiment. As a result, in the slope failure, the ground displacement process increases the risk of collapse as the inverse displacement approaches zero. It is closely related to the prediction of precursor. In all cases, increase in displacement and reverse speed of inverse displacement with time was observed during the slope failure, and it is very important event for monitoring collapse phenomenon of risky slopes. In the future, it can be used as disaster prevention technology to contribute in reduction of landslide damage and activation of measurement industry.

• Journal of the Korean Geosynthetics Society
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• v.17 no.2
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• pp.9-18
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• 2018

In this study, a field model experiment was performed to analyze the bahavior of slope during failure. It was analyzed through x-MR control chart method with inverse displacement and K-value. As a result, the portent was confirmed at 4 minutes before slope failure in Case 1. The change of the control limit line according to moving range was analyzed and it was effective to apply K = 3. Use of the inverse displacement and x-MR control chart method will be useful for the prediction of abnormal behavior through quick and objective judgment. Prediction of slope failure using control chart method can be used as basic data of slope measurement management standard, and it can contribute in reduction of life and property damage caused by slope disaster.

• Journal of the Korean GEO-environmental Society
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• v.20 no.6
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• pp.15-22
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• 2019

In this study, the hazard areas are identified by using the Newmark displacement model, which is a predictive model for identifying the areas at risk of landslide triggered by earthquakes, based on the results of field survey and laboratory test, and literature data. The Newmark displacement model mainly utilizes earthquake and slope related data, and the safety of slope stability derived from LSMAP, which is a landslide prediction program. Backyang Mt. in Busan where the landslide has already occurred, was chosen as the study area of this research. As a result of this study, the area of landslide prone zone identified by using the Newmark displacement model without earthquake factor is about 1.15 times larger than that identified by using LSMAP.

• Tunnel and Underground Space
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• v.13 no.3
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• pp.207-214
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• 2003

To obtain Digital Elevation Model(DEM) from an exposed rock mass, techniques such as laser scanning and digital stereo photogrammetric technique are recently applied. We have obtained the DEM of the rock slope using above techniques in this study, and examined a suitability and improvement of the photogrammetry for the rock slope by overlapping the DEM. This study can be applied to the measurement of fracture orientations, the prediction of rock joint network, and the analysis on the change of the rock slope.

• Geomechanics and Engineering
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• v.30 no.2
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• pp.187-199
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• 2022

Kriging metamodel, as a flexible machine learning method for approximating deterministic analysis models of an engineering system, has been widely used for efficiently estimating slope reliability in recent years. However, the autocorrelation function (ACF), a key input to Kriging that affects the accuracy of reliability estimation, is usually selected based on empiricism. This paper proposes an adaption of the Kriging method, named as Genetic Algorithm optimized Whittle-Matérn Kriging (GAWMK), for addressing this issue. The non-classical two-parameter Whittle-Matérn (WM) function, which can represent different ACFs in the Matérn family by controlling a smoothness parameter, is adopted in GAWMK to avoid subjectively selecting ACFs. The genetic algorithm is used to optimize the WM model to adaptively select the optimal autocorrelation structure of the GAWMK model. Monte Carlo simulation is then performed based on GAWMK for a subsequent slope reliability analysis. Applications to one explicit analytical example and two slope examples are presented to illustrate and validate the proposed method. It is found that reliability results estimated by the Kriging models using randomly chosen ACFs might be biased. The proposed method performs reasonably well in slope reliability estimation.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.260-260
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• 2017

This study aims to compare the performance of TRIGRS (Transient Rainfall Infiltration and Grid-based Regional Slope-stability model) and TiVaSS (Time-variant Slope Stability model) in the prediction of rainfall-induced shallow landslides. TRIGRS employs one-dimensional (1-D) subsurface flow to simulate the infiltration rate, whereas a three-dimensional (3-D) model is utilized in TiVaSS. The former has been widely used in landslide modeling, while the latter was developed only recently. Both programs are used for the spatiotemporal prediction of shallow landslides caused by rainfall. The present study uses the July 2011 landslide event that occurred in Mt. Umyeon, Seoul, Korea, for validation. The performance of the two programs is evaluated by comparison with data of the actual landslides in both location and timing by using a landslide ratio for each factor of safety class ( index), which was developed for addressing point-like landslide locations. In addition, the influence of surface flow on landslide initiation is assessed. The results show that the shallow landslides predicted by the two models have characteristics that are highly consistent with those of the observed sliding sites, although the performance of TiVaSS is slightly better. Overland flow affects the buildup of the pressure head and reduces the slope stability, although this influence was not significant in this case. A slight increase in the predicted unstable area from 19.30% to 19.93% was recorded when the overland flow was considered. It is concluded that both models are suitable for application in the study area. However, although it is a well-established model requiring less input data and shorter run times, TRIGRS produces less accurate results.

• Transactions of Materials Processing
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• v.20 no.4
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• pp.284-290
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• 2011

The front end bending(FEB) behavior of material that usually occurs in plate rolling is investigated. In this paper, a rollbite profile map approach that systematically predicts the FEB slope is presented. It is based on the concurrent use of shape factors and reduction ratios to ensure an accurate value of the FEB and its slope. In order to obtain the unit roll-bite profile map, the FEB slope model was decomposed into a temperature deviation component and a roll-velocity deviation component. By mapping the results of a series of finite element analyses to the unit functions of the roll-bite profile map, it was possible to obtain a realistic prediction of the FEB slope applicable to an actual plate rolling process. Thereby, the usefulness of the present approach is clearly demonstrated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.6
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• pp.1395-1404
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• 1994

Transverse bed slope in bend is a subject of scientific investigation since it provides the necessary information for channel design and protection of hydraulic structures (bank, bridge, etc), and study of river morphology. In this paper, selected models were examined and compared for the value of prediction of the transverse bed slope in curved alluvial channels(project area), by using field data, and fitting model was proposed. All models that related the local transverse bed slope to mean flow characteristics were alike in the sense that they predicted the local transverse bed slope to be proportional to the ratio between depth and radius of curvature. The difference among the models was related with the factor of proportionality, K. Also, measured transverse bed slope was correlated to mean velocity, maximum depth, and density Froude number in channel bend. In this paper selected models were compared for the prediction of the transverse bed slope using Odgaard's experiment (obtained in Sacramento River bend), so Odgaard89 model was closely related with real transverse bed slope.