• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.509-522
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• 2010

There is a increasing trend in disaster occurrence due to steep-slope failures in urban area during typhoon and torrential rain season in Korea. The underlying hazards that cause slope failure are mainly linked with urbanization and industrialization. To minimize the disaster damages by slope failure, objective and unified evaluation approached are desired. Since currently available evaluation checklists are developed for specific purposed, there is a limitation to adapt those checklists for stability evaluation in natural terrain. This study proposes an improved evaluation checklist based on the comparison of previous checklists and applicability and feasibility are analyzed implementing field application.

• Explosives and Blasting
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• v.26 no.2
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• pp.38-44
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• 2008

Recently, planning road construction in South Korea is focused on upgrading of the existing road by rerouting or restructuring. For this, roads under current construction in Korea go for more straight in its alignments and routing. Straight routing makes it all the more required to construct many mountain tunnels and bridges in Korea where mountains are so widely spread. Some portal of mountain tunnel is not rarely planed at high steep slope of mountain valley where it is not easy to secure working space for tunnel excavation. Reverse excavation is an alternative measure for excavation of tunnel portal at high steep slope. Construction in reverse excavation method has three important points requiring careful consideration: 1)planning of pilot tunnel in proper width, height, and length etc., 2)measure against the effect of one-side earth pressure to the direction of tunnel portal, 3)securing tunnel safety against shallow ground condition at portal zone. This paper intends to suggest applicable range of pilot tunnel for reverse excavation at the portal zone located at high steep slope, and shows result of study on the appropriateness of a reverse excavation by means of 3D numerical analysis. Result of 3D numerical analysis for reverse excavation at high steep slope shows that pilot tunneling will be applicable to start from the point $20{\sim}25m$ before the portal from inside the tunnel.

• Journal of Korea Water Resources Association
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• v.49 no.6
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• pp.529-536
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• 2016

The existing methods to estimate the maximum scour depth in the bend of steep gravel bed channel have been evaluated by the hydraulic movable-bed experiments. In the $90^{\circ}$ bend steep-slope channel paved with the fluvial gravels which are uniform in size and have a mean diameter of 43mm, the maximum scour depths due to the flow discharge and the gradient of bed slope have been investigated and compared with the scour depth computed from the equations. The local scour has occurred in conditions that the bed slope is steeper than 0.02 and the $F_r$ is greater than 0.95. Except Lacey's equation and Zeller's equation, the existing methods computing the maximum scour depth overestimate the maximum scour depth in the steep channel with the very coarse gravel bed. However, Lacey's equation with the bed material size and Zeller's equation considering the approach channel gradient and the bend angle may be relatively used to estimate the scour depth in bend of the steep gravel-bed river.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.3_4
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• pp.429-440
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• 2003

The purpose of this study is to classify the types of men's shoulders through the criteria which represent the characteristic of men's shoulders. In addition, we introduce new bodice patterns depending on our classification. We have the fo11owing conclusions based on our sample size of 200 men's shoulders: 1. The result of factor analysis indicates that six factors are extracted and they consist of 62.3% of total variance. We then choose three factors as standard items for our classification of the shape of men's shoulders. 2. We divide the shape of shoulders into three categories: bent, slopeness, and thickness. Each category is divided into three subcategories. (a) Bent: If one's shoulders are bent forward or backward, then we call them front or back-bent type. Otherwise, they are called standard-bent type. (b) Slopeness: If one's shoulders have an easy or steep slope, then we call them easy or steep slope type. Or else, they are called standard slope type. (c) Thickness: If one's shoulders are thick or thin, then we call them thick or thin type. Otherwise, we call them standard thick type. 3. According to the frequency based on our data entries of 200 men's shoulders, we introduce five new types of men's shoulders. 76.5% of examined men's shoulders belong to one of these five types: (a) 8.0% of standard slope and back-bent type: (b) 9.5% of easy slope and standard-bent type; (c) 45.5% of standard slope and standard-bent type; (d) 5.5% of steep slope and standard-bent type; (e) 8.0% of standard slope and back-bent type. 4. The suitability of new basic bodice patterns based on the types of men's shoulders are demonstrated by the high approval rate of the subjects who participate in testing.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1093-1102
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• 2009

This study was focused on analyse Nonpoint source characteristics from Flat slope field and Steep slope field. We performed Storm-water monitering for obtain flow data and concentration data. Totally, eleven times Event was occurred. We calculated EMC(Event Mean Concentration) and Pollutants Loads using data we obtained. As a result, steep slope field has more discharge than flat field. SS value, one of the water quality contents, has largest variation and T-N has least variation. There is runoff differences even though events has same rainfall. We assume that not only amount of Rainfall, but also Rainfall Duration Times, Intensity, Number of Previous Non-precipitation days can affect to Run-off.

• Journal of the Korean Geographical Society
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• v.40
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• pp.15-29
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• 1989

The purpose of this study is to analyze the Slope Angles and Summit Levels in the relation with the geological structures in the Taehwa River Basii where the NNE-SSW trending Yangsan fault and subsiduary fault are well developed. The mean slope angle in the Taehwa river basin is 12.18$^{\circ}$. The mean slope is higher in the volcanic and metamorphic terrain than in the area of granitic and sedimentary rocks. In view of a slope angle, the area can be divided into four categories, that is, low plains (0-5$^{\circ}$), hilly gentle slopes (5-15$^{\circ}$), moderate steep mountain slope (15-25$^{\circ}$), and steep mountain slope (over 25$^{\circ}$). The analysis of summit level exhibits that the mean of the highest points in the Taehwa River Basin composed mainly of the volcanic and metamorphic rocks is 327m.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.930-939
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• 2009

Most of steep slope failures occurring in Korea have appeared during the localized heavy rain period, whereas the evaluation model of a disaster vulnerability analysis that has been proposed to date, has been prepared in consideration only of external factors comprising geographical features. This study calculated a wetness index and a contributory area which delivers moisture to the upper slant surface during the rainfall period, and also conducted a disaster vulnerability analysis in consideration of the convergence of surface water as well as the water system created during the occurrence of rainfall by including a curvature that shows a close relevance with the shape of the minute water system that is created temporarily during the occurrence of rainfall and with the convergence and divergence of surface water. When compared with a steep slope failure occurring within a selected model district in order to verify the prepared disaster analysis, a landslide occurring in the model district had emerged in a region in which the disaster vulnerability analysis was high and the density of the minor water system was also high. If these research results are extended nationwide, it is the most effective to use a disaster vulnerability analysis and the density of the minute water system; and it is supposed to be the simplest and the most effective method for preparing a disaster analysis of mountainous land shape such as the model district.

• Journal of the Korean Geotechnical Society
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• v.38 no.12
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• pp.79-89
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• 2022

Every summer in our country, an accident occurs, in which the retaining wall on a steep slope collapses due to torrential rain. According to the data on the results of steep slope risk assessment in 2019, over 780 retaining walls are below grade C; therefore, preparing for countermeasures is urgent. However, due to the limited budget for the repair and reinforcement of these retaining walls, it is necessary to discuss the investment prioritization. In this study, a prioritization method was proposed at the network and project levels along with the review of the revised criteria of disaster risk assessment in the steep slope retaining wall, and an application research in the network level was conducted for six retaining walls. Moreover, it is proposed that the priority index was determined by using the actual cost for repair and reinforcement in determination of the project level prioritization.

• Journal of the Society of Disaster Information
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• v.16 no.1
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• pp.111-122
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• 2020

Purpose: In order to manage the steep slopes effectively, this study diagnose problems in the procedure of steep slopes management and propose Improved frame work is intended to mitigate human and property damage Method: Problems in the system are drawn through review of procedures for designation of collapse risk zones and fied investigation, interviews with local governments, and expert advice. Result: The selection stage, the subject of the management, the management method, and the factors that need to be improved by the management stage before the evaluation are derived. Conclusion: This paper identified the problems raised and drew improvements and presented the research direction for the development of the new system (plan) and the steep slope site.

• The Journal of Engineering Geology
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• v.22 no.2
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• pp.185-194
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• 2012

The efficient maintenance and management of steep slopes often require excessive professional resources and quantitative investigations. Therefore, it is important to develop technology for objective scientific site investigations and quantitative evaluations of steep slopes. This study proposes a 'Mobile System' for steep slopes in order to improve the effectiveness of site investigations compared with conventional methods using anevaluati on table. By analyzing site investigations and desktop studies, the required software and hardware are identified to develop the 'Mobile System', consisting of a 'Field Information Input System' and an 'Analysis System'. The applicability of the system is verified by its application to an area with steep slopes affected by debris flows. The use of this system is expected to increase the efficiency of maintaining steep slope sand to reduce the time and resources required.