• Journal of the Korean Society of Industry Convergence
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• v.20 no.2
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• pp.125-132
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• 2017

The slope of the road in the forest area has a characteristic of steep slope, so natural disasters such as slope collapse occur. The slope displacement observation technique according to landslide is being studied as a method to observe a wide area and a method to observe a small area. This is a study on high-precision digital map generation using ground LiDAR. It is possible to create a high - precision digital map by minimizing the US side using the 3D LiDAR in the steep slope area where the GPS and Total Station measurement are difficult in the maintenance of the danger slope area. It is difficult to objectively evaluate whether the contour lines generated by LiDAR are correct and it is considered necessary to construct a test bed for this purpose. Based on this study, if terrain changes such as landslides occur in the future, it will be useful for measuring slope displacement.

• Journal of Korean Society of Forest Science
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• v.105 no.4
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• pp.435-440
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• 2016

This study was carried out to examine of soil physical property and crack shape by collapse process on landslide area (by land creeping) in Hadong, Gyeongnam. We investigated morphological characteristics (length, depth, cut slope) between main crack and local crack, soil physical properties change between undisturbed section and disturbed section. As a result, morphological characteristics of crack showed no significant difference main crack between local crack. In case of soil physical property variation, soil liquid phase was significantly higher at 31-40 cm of soil depth in disturbed section. And this result is likely to be due to site factors.

• Journal of the Korean GEO-environmental Society
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• v.19 no.9
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• pp.29-36
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• 2018

Several studies have been conducted on monitoring system and automatic measuring instruments to prevent slope failure in advance in Korea and overseas. However, these studies have quite complex structure. Since most of the measurement systems are installed on the slope surface, the researches are carried on the measurement system that detects sign of slope collapse in advance and alerts are still unsatisfactory. In this study, slope collapse experiments were carried out to understand the slope failure mechanism according to rainfall conditions. The water content and displacement behavior at the early stage of the slope failure were analyzed through the measurement of the ground displacement and water content. The results of this study can be used by local government as a basic data for the design of slope failure alarm system to evacuate residents in case of slope failure or landslide due to heavy rainfall.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.5
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• pp.51-60
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• 2017

This research is a basic study to minimize the risk of disaster (earthquakes and landslides) for rural residential houses. In this study, three-dimensional numerical analysis was performed by varying the diameter (D), thickness (T) and the spacing of longitudinal members (C.T.C) of duralumin and galvanized steel pipe as the materials of main members in order to carry out the analysis of the dimension and the applied load of shelter for disaster prevention, and to evaluate the eligibility of members that can satisfy safety and usability. From the evaluation results of the member eligibility by the above numerical analysis, it was found that duralumin has a great influence on the member diameter (D) and thickness (T), and in the case of galvanized steel pipe, its spacing of longitudinal members has a huge amount of influence over the member force, so it is considered that the duralumin and galvanized steel pipe materials can be used as materials for the main members of disaster prevention shelters in terms of safety and usability.

• Journal of Korean Society of Disaster and Security
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• v.14 no.4
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• pp.29-36
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• 2021

Recently, due to climate change, the slope is increasing, and the risk of steep slope disasters such as the occurrence of slope collapse in the east coast and Busan region in 2019 and the Gokseong landslide in 2020 is increasing. Particularly, most national parks are made up of mountainous areas, and the risk of disasters on steep slopes is increasing. As the ground of the national park is aging and the weathering and jointing of the bedrock are accelerating due to climate change, the slope collapse and rockfall are increasing, and the annual number of visitors is increasing, it is necessary to manage steep slopes adjacent to multi-use facilities with many users. In this study, dangerous steep slopes that affect multi-use facilities in national parks were analyzed using GIS and verified through field surveys. As a process for extracting steep slopes adjacent to multi-use facilities in national parks, the slope was made in DEM and slopes of 34 degrees or higher were extracted. The difference between the maximum and minimum heights of the extracted slopes was used to confirm that the slopes met the standard for steep slopes, and the analysis of the slope direction was used to confirm whether it had an effect on the multi-use facilities. After that, precision aerial images and field photos were analyzed to finally identify risks at 4 sites, and field surveys were conducted. As a result of the field survey, all 4 sites were found to be steep slopes, 3 were graded D and 1 was graded C, so it was confirmed that management was required as a risk of collapse. All steep slopes extracted through GIS were found to be dangerous, so it is judged that the extraction of steep slopes through GIS would be appropriate.

• Geomechanics and Engineering
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• v.32 no.1
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• pp.111-123
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• 2023

The slope of an open cut tunnel is located above the exit of the Leijia tunnel on the Changgan high-speed railway. During the excavation of the open cut tunnel foundation pit, the slope slipped twice, a large landslide of 92500 m³ formed. The landslide body and unstable slope body not only caused the foundation pit of the open cut tunnel to be buried and the anchor piles to be damaged but also directly threatened the operational safety of the later high-speed railway. Therefore, to study the stability change in the slope of the open cut tunnel under heavy rain and excavation conditions, a 3D numerical calculation model of the slope is carried out by Midas GTS software, the deformation mechanism is analyzed, anti-sliding measures are proposed, and the effectiveness of the anti-sliding measures is analyzed according to the field monitoring results. The results show that when rainfall occurs, rainwater collects in the open cut tunnel area, resulting in a transient saturation zone on the slope on the right side of the open cut tunnel, which reduces the shear strength of the slope soil; the excavation at the slope toe reduces the anti-sliding capacity of the slope toe. Under the combined action of excavation and rainfall, when the soil above the top of the anchor pile is excavated, two potential sliding surfaces are bounded by the top of the excavation area, and the shear outlet is located at the top of the anchor pile. After the excavation of the open cut tunnel, the potential sliding surface is mainly concentrated at the lower part of the downhill area, and the shear outlet moves down to the bottom of the open cut tunnel. Based on the deformation characteristics and the failure mechanism of the landslides, comprehensive control measures, including interim emergency mitigation measures and long-term mitigation measures, are proposed. The field monitoring results further verify the accuracy of the anti-sliding mechanism analysis and the effectiveness of anti-sliding measures.

• Journal of Environmental Science International
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• v.22 no.11
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• pp.1529-1538
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• 2013

Disasters like mountain landslides and collapse in cutting areas claim many a life and cause economic losses, involving much effort and expenses for their recovery. This study has surveyed and analyzed incident of disasters that had occurred on the sloping sides in Korea for the past 13 years in an effort to relieve damage caused by disasters on the sloping sides. The analysis confirms that while the major cause of disasters on the sloping side was storms in the past, frequency of disasters on sloping sides caused by local downpour is steadily on the rise. In addition, while disasters were concentrated in Gangwon Province, a mountainous region of the country, frequency of disasters occurring on the sloping sides is steadily increasing recently on the sloping sides in downtown areas in Seoul, Gyeonggi-do and so forth, attributing a large percentage of disasters to sloping sides. Data surveyed and analyzed in this study are thought to be applicable as basic data for the establishment of effective measures for the prevention of disasters occurring on the sloping sides in the days to come.

• Journal of the Korean GEO-environmental Society
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• v.10 no.2
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• pp.69-76
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• 2009

In this study, design method for debris flow and drift wood dams used in Japan was evaluated to develop currently available design method practiced in Korea. In Japan, represented a similarity in the aspects of topography and the climate compared with Korea, casualties due to debris flow, landslide, and collapse of cliff as well as earthquake, have been reported every year. Especially, debris flow had often occurred during heavy rainy season rather than due to Typhoons or localized torrential thunderstorms. Since the characteristic of the debris flow reveals in the middle of water flow and soil behaviors, the behavior of debris flow associated with drift wood was not fully understood at this moment and therefore empirical design method to design debris flow dam is adopted in the practice and currently used in Japan. Based on the result of this study, modification of debris flow design method used in Korea are presented.

• The Journal of Engineering Geology
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• v.23 no.3
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• pp.257-269
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• 2013

Prevention plans for landslide and slope disasters should be appropriate for a country's budget when considering a systematic investment plan. The systematic management of slopes adjacent to national highways should incorporate reasonable investment risk and the expected degree of damage should be calculated by considering the investment priorities. In terms of priority of investment, the major factors used to determine the degree of hazard are gradient, soil characteristics, RMR (Rock Mass Rating), stability interpretation, type of discontinuities, and history of collapse, among others. The likely consequences of slope failure can be determined by considering traffic volume, the number of lanes, and average vehicle risk. We performed such calculations regarding the priority of investment and performed a regression analysis for 392 slopes located in Yeongseo region, Gangwon province. The calculation results show that collapsed slopes have a higher priority for investment, as do slopes with a high proportion of dangerous sections and locations in valleys.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.3
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• pp.367-374
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• 2009

Every year there are great socio-economic loss and damage caused by landslides in steep slopes. According to recent statistics, the percentage of casualty due to breakdown in steep slopes was 27.3% of all natural disasters occurring over the past decade($1998{\sim}2007$). Therefore, the nationwide scale survey on the landslide susceptibility was made to recognize the status quo for appropriate troubleshooting measure against the collapse of steep slopes. Nevertheless, few dent that the data collected is not sufficient to grasp the overall understanding of the onsite situation due to lack of spatial information. As a result, the study aims to develop a program enabling to send on site topological data and prefixed data-gather criteria directly to the central management server in real-time basis. It will be conducted through mobile devices and portable GPS system, accordingly. This program is expected to be implemented as an efficient application tool of slope spatial information acquisition.