• Steel and Composite Structures
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• v.47 no.4
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• pp.451-454
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• 2023

Landslides are one of the natural disasters that cause a lot of financial and human losses every year It will be all over the world. China, especially. The Mainland China can be divided into 12 zones, including 4 high susceptibility zones, 7 medium susceptibility zones and 1 low susceptibility zone, according to landslide proneness. Climate and physiography are always at risk of landslides. The purpose of this research is to prepare a landslide hazard map using the Hierarchical Analysis Process method. In the GIS environment, it is in a part of China watershed. In order to prepare a landslide hazard map, first with Field studies, a distribution map of landslides in the area and then a map of factors affecting landslides were prepared. In the next stage, the factors are prioritized using expert opinion and hierarchical analysis process and nine factors including height, slope, slope direction, geological units, land use, distance from Waterway, distance from the road, distance from the fault and rainfall map were selected as effective factors. Then Landslide risk zoning in the region was done using the hierarchical analysis process model. The results showed that the three factors of geological units, distance from the road and slope are the most important have had an effect on the occurrence of landslides in the region, while the two factors of fault and rainfall have the least effect The landslide occurred in the region.

• Geomechanics and Engineering
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• v.38 no.6
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• pp.611-620
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• 2024

The slope stabilization method is constructed on bedrock, but performance degradation occurs during an impact (earthquake, blasting, etc.) after construction, which may affect service life and factor of safety. In particular, the top-down method implies the possibility of damage caused by blasting vibration due to the construction procedure. However, the current blasting design only reflects damage to nearby facilities, so there is a limit in its ability to assess the damage of reinforcement methods caused by blasting vibration within the scope of influence. In this study, we aim to evaluate problems and damage levels caused by close blasting effects on rock-integrated structures, such as panel-type retaining walls, anchor-combined structures, and small nails, which are mainly constructed using the top-down method. We will also analyze factors affecting long-term performance according to changes in conditions after construction, such as tunnel excavation, to establish optimal design measures.

• Journal of the Korean Geosynthetics Society
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• v.11 no.4
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• pp.17-25
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• 2012

In this study, it was carried out reliability analysis and slope stability analysis in a standard cross-sectional embankment on high speed railway. It was confirmed that changing tendency of safety factor with various parameter of each soil materials properties and trends of the probability of failure according to the reliability index. The results have shown that a safety factor were relatively large affected an cohesions and internal friction angle of soil compared to the unit weight of soil. Also, most of the standard cross-sectional embankment in high speed railway was generally evaluated the level of below average (below average) by the reliability analysis according to criterion in US. Army but the 12m height of dry embankment case was shown bad condition as Poor.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.208-214
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• 2014

Vehicle dynamic states used in various advanced driving safety systems are influenced by road geometry. Among the road geometry information, the vehicle pitch angle influenced by road slope and acceleration-deceleration is essential parameter used in pose estimation including the navigation system, advanced adaptive cruise control and others on sag road. Although the road slope data is essential parameter, the method measuring the parameter is not commercialized. The digital map including the road geometry data and high-precision DGPS system such as DGPS(Differential Global Positioning System) based RTK(Real-Time Kinematics) are used unusually. In this paper, low-cost cascade extended Kalman filter(CEKF) based road slope estimation method is proposed. It use cascade two EKFs. The EKFs use several measured vehicle states such as yaw rate, longitudinal acceleration, lateral acceleration and wheel speed of the rear tires and 3 D.O.F(Degree Of Freedom) vehicle dynamics model. The performance of proposed estimation algorithm is evaluated by simulation based on Carsim dynamics tool and T-car based experiment.

• Geotechnical Engineering
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• v.7 no.2
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• pp.67-82
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• 1991

When bridge abutments are constructed on pile foundations in unstable slope, horizontal deflections may be developed in the piles and the abutments due to lateral soil movements arisen from backfills. In most of the above mentioned cases, the piles are situated in a soft layer where lateral earth pressures are developed between the piles and the soils. The undesirable lateral earth pressures decreases the stability of the piles. However, the piles may have a preventive effect against lateral soil movements and improve the stability of the slope. For the stability problem of such slope containing piles in a row, two kinds of analyses for the slope-stability and the pile-stability have to be performed. The whole stability of bridge abutments on pile foundation can be obtained only by the stabilization for both the slope and the piles. A reasonable analytical method for the bridge abutments on pile foundation was established in this study By use of the analytical method for an example, several factors which influence affect the stability of bridge abutment were investigated. Finally, for the bridge abutment subjected to lateral deflections damage, the fixity condition of pile head was investigated.

• Journal of the Korean Geotechnical Society
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• v.33 no.4
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• pp.5-15
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• 2017

Three-hinge failure occurs in a jointed rock slope with a joint set parallel with slope and a conjugate joint set. Limit Equilibrium Method (LEM) and Finite Element Method (FEM) which are commonly used for slope design, are not suitable for evaluating stability against three-hinge failure, and this study performed parametric study to analyze the failure mechanism and to find influence factors causing three-hinge failure using UDEC which is a commercial two-dimensional DEM based numerical program. Numerical analyses were performed for various joint structural conditions and joint properties as well as ground water conditions. It was found that pore water pressure is the main factor triggering the three-hinge failure and the mode of failure depends on friction angle of basal joint and bedding joint set. The results obtained from this study can be used for adequate and economic footwall slope reinforcement design and construction.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.2
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• pp.169-177
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• 2000

The modelling technique on the terrain of real-world in geo-spatial information system is a primary element for geo-information processing. This paper is designed to make use of TIN in geo-spatial information system and study the development and application of high-precision 3-D spatial analysis technique applied to terrain features. According to this research, MODEL 3 applied to breakline in mild slope/steep slope and MODEL 2 applied to peak in complex region show relatively low RMSE. This consequence proves that these two models have high precision in comparison with other models. This study also finds out optimal routines in the estimation method of slope grade and in the construction method of surface. N_T, LSP_T and LSQ_T in mild slope, N_T in steep slope, and LSQ_T in complex region turn out to be the optimal routines for high-precision 3-D spatial analysis.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.262-267
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• 2008

Recently, landslides frequently occur on natural slope and/or man-made cut slope during periods of intense rainfall. With a rapidly increasing population on or near steep terrain, landslides have become one of the most significant natural hazards. Thus, it is necessary to protect people from landslides and to minimize the damage of houses, roads and other facilities. To accomplish this goal, many landslide monitoring systems have been developed throughout the world. In this paper, a simple landslide detection system that enables people to escape the endangered area is introduced. The system is focused on the debris flows which happen frequently during periods of intense rainfall. The system is based on the wireless sensor network (WSN) that is composed of wireless sensor nodes, gateway, and remote server system. Wireless sensor nodes and gateway are deployed by commercially available Microstrain G-Link products. Five wireless sensor nodes and one gateway are installed at the test slope for detecting ground movement. The acceleration and inclination data of test slope can be obtained, which provides a potential to detect landslide. In addition, thresholds to determine whether the test slope is stable or not are suggested by a series of numerical simulations, using geotechnical analysis software package. It is obtained that the alarm should be issued if the x-direction displacement of sensor node is greater than 20mili-meters and the inclination of sensor node is greater than 3 degrees. It is expected that the landslide detection method using wireless senor network can provide early warning where landslides are prone to occur.

• Journal of the Korean GEO-environmental Society
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• v.25 no.8
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• pp.5-11
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• 2024

Due to the high proportion of mountainous terrain in Korean territory and the concentration of heavy rainfall during the summer season, concerns arise about the potential decrease in slope stability caused by rainfall. Installing slope drainage facilities mitigates the rise in groundwater levels due to infiltration, thus enhancing slope stability. Horizontal drains, classified as auxiliary facilities among drainage systems, lack established installation standards and related research. Slopes with installed horizontal drains have been confirmed to exhibit higher safety factors compared to those without. Furthermore, the safety factor of mimicking horizontal drains by increasing the permeability coefficient of the surrounding ground was compared with that of the conventional simulation method using the Drain function. As a result of the comparison, it was confirmed that the installation length showed better drainage performance than the installation angle in the drainage performance of the horizontal drainage hole, and it was judged that the installation length was a more important factor.

• Journal of the Korean Society for Railway
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• v.11 no.2
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• pp.158-164
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• 2008

Abstract Infiltration of rainfall that may lead to reduce resistance force due to reduction of matric suction and to increase driving force due to increase of self weight makes the slope fail. There are many specifications to make slope stable based on factor of safety. Although result of slope stability analysis satisfy the specifications, slope failures triggered by rainfall are frequently occurred in reality because slope stability analysis cannot consider uncertainty of each soil properties. This is why conventional analysis has limitation and development of alternative method is needed. So it is suggested to adopt the reliability analysis rather than design based on factor of safety into designing safer structure. Through the evaluation of handicaps for the factor of safety based design, calculation of soil properties by site investigation, and reliability analysis considering distribution of each soil properties, distribution of failure probability in railway slope is obtained. Then, Risk assessment of slopes in Korean railway is executed from the results. Damage loss and incoming loss are considered as the loss. Using these results, it is possible to make proper countermeasure or efficient maintenance.