• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.1602-1610
• /
• 2005

In this study was investigated and analyzed of damage characteristics for infrastructures by typhoon that have been many occur. The objective Structures were the road and hydraulic structure. The road structure was included the cut-slopes, retaining walls and bridges. The hydraulic structure is divided with the dike, small-scale dam, reservoir and floodgate. The analysis result of the bridge damage cause is river bottom height increase and passage ability decrease. The principal damage reasons of the cut-slope structure are weakening the ground due to the localized torrential downpour and drainage defective. Also, the principal damage reasons of the small-scale dam, reservoir, dike and the floodgate are continuous collapse of dike beside the floodgate.And we divided a typhoon damage occurrence cause with artificial and natural. As the result of analysis, the many damage occurrence cause will be removed by system improvement and technical development.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.26 no.3
• /
• pp.8-18
• /
• 1998

This study was to make a effective seed mixture types with Korean native plants by researching te seed timing of suitable woody plants and competitive germination results of various plants for the purpose of cut-slotes revegetation. The results are summarized as follows. 1. In field polystand experiment, comparative among severalcomposition combination for early coverage shows good condition. 2. In combination for early-coverage, mixture of native woody plants only seeded in May and June shows over 90% coverage. It was not inferior to the other mixture types. So mixture of Albizzia Julibrissin, Cymbopogon doeringii, Alnus hirsuta and Indigfera pseudo-tinctoria is able to use to mixture type. 3.In case of combination for scenic beauty, Rhus chinensis shows low germination in the mixture for scenic beauty. But 90 days after seeded in May, it recorded maximum 44 cm height, seeded in June recorede 18 cm height. 4. Lespedeza crytobotrya shows good elongation in the combination for early coverage and scenic beauty, but that effects on elongation of other plants. So, it demands close investigation about suitable mixing rate of plants. 5. Alnus hirsuta, Pinus thunbergii, Betula platyphylla, Spiraea prunifolia var. simpliciflora have been rarely germinated. So, the mixture of these plants wasn't adequate to use for revegatation.

• The Journal of Engineering Geology
• /
• v.11 no.3
• /
• pp.303-313
• /
• 2001

A cut-slope near Guam-Ri Hwado-Eup Namyangju-Si Kyunggi-Do collapsed during a heavy rainfall over 400mm at 28th of August 2000. The cut-slope collapse reportedly developed mainly by block sliding along a set of discontinuities, although slope angle of the cut-slope was 40$^{\circ}$(1:1.2) that agrees with the road construction criteria. This study aims to analyze differences and correlations among several data-collecting methods limited to discontinuity analysis related with cut-slope collapse. This study started with analysing discontinuity surface characteristics, geology of the country rock and orientations of the discontinuities directly related with the collapse. Analysis of aerial photos around the study area provided regional lineament data, and discontinuity plane description and measurements were collected from core logging and Borehole Image Processing System (BIPS). Spearmans correlation ranking coefficient method was used to get correlation of discontinuity planes according to analysis methods. The result suggests that the correlation coefficient is ${\gamma}_s$ = 0.91 Plus, stability analysis of discontinuity plane orientation data using equal-area stereonet revealed that the study area is unstable to planar failure. This study suggests that the cut-slope angles currently applied should be shallower and that significant attention is required to orientation distribution of discontinuities existed in cut-slopes studies.

• The Journal of Engineering Geology
• /
• v.19 no.3
• /
• pp.401-408
• /
• 2009

Old national Road No. 59 that connects Danyang and Gagok has 35 dangerous cut slopes. It is relatively narrow and has a poor alignment. The torrential rains in 2002 and 2006 has caused numerous slope collapses, landslides and road settlements in this area. The old road's high risk level lead to the planning and construction of a new national road. During the construction of the new road in December 2006, the right side of Dugcheon Tunnel entrance has collapsed and tension cracks were observed on the district road above the tunnel. In order to determine the cause of failure, intensive field investigation and monitoring cracks were performed together with Lower Hemisphere Projection Analysis, Limit Equilibrium Analysis and Finite Difference Analysis.

• Journal of the Korean Geotechnical Society
• /
• v.17 no.6
• /
• pp.111-121
• /
• 2001

Rockfall protection fences are used for diminishing rockfall damage in roads side slopes. In order to install the fences in effective way, the conditions of rock slopes and total predicted impact energy of fa11ing rock should be considered. However, the fences have been constructed without any consideration for lithology, height and slope angle of rock slope in Korea. In addition, the information about the performance of the protection fences, which should be evaluated by in-situ test or laboratory test in order to check out the practical use in the field, is not available. Therefore, in design manual for the rockfall protection fence, the specific details for the installation of this type of fence are not provided yet. The full sized rockfall in situ test was carried out for the calculation of falling energy of rock and the evaluation of the maximum energy absorbing capacity of fence. For this test, the rock slopes whose heights are about 20 m and dip angle of 65 degree, have been chosen. This is because those geometries are mean height and slope angle of most road cut slopes along Korean national highway. Based on the preliminary simulation procedure, four different sizes of concrete ball (0.7, 1.3, 2.3 and 4.3 ton) were prepared and flour different types of protection fence were constructed. The results of this test provide information about the maximum energy absorbing capacity of the fence, kinetic energy of rockfall and restitution coefficient, and these results can be utilized in the establishment of rockfall fence design and construction manual.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.4 no.3
• /
• pp.49-54
• /
• 2001

It is common that the soil layer is a few meters below the earth's surface and the rock mass is below the soil layer in the view of geological characteristics in Korea. And the boundary between rock and soil is clearly divided. When dealing with the stability of rock masses, as in the case of rock slopes or dam foundations, the majority of the collapses is not within the soil layer, but within the soil-rock boundary. Therefore it is important to identify the shear strength characteristics between soil-rock boundary. And then in the method of reinforcement on landslide this chose a cut slope near Daemo elementary school in Seoul, surveyed shear strength between soil-rock contacts and considered a large scale collapse using a limit equilibrium method.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.10c
• /
• pp.19-27
• /
• 2001

Early detection of premonitory symptom of slope movement ensures tremendous saving of lives and repair costs from catastrophic disaster. Therefore, it is essential to constantly monitor the performance and integrity of both reinforced and un-reinforced cut slopes. We developed a novel monitoring system by using tension wire sensors. It's advantages are highly sensitivity, simple installation, large displacement measurement, durability of system, capability of remote sensing. Real-time measurement of slope surface movement is shown graphically and it gives a warning when the monitored value exceeds a given threshold level so that any sign of abnormal slope movement can be easily perceived.

• Journal of the Korean Society of Safety
• /
• v.29 no.6
• /
• pp.111-118
• /
• 2014

While large-sized facilities (type I II) have been managed systematically after the establishment of the Special Law for Safety Management on Facility, the management of small-sized facilities is relatively poor. The small-sized facilities have been managed by The Basic Law for Disaster and Safety Management, however, it is hard to manage them systematically as related standards are not established. Therefore, this study proposed the management plans for including the facilities such as some road tunnels and utility tunnels, which have the definite manager and a high possibility to harm the public, into type I and II facilities. In addition, it proposed the reinforcement plans of safety management for small-sized and vulnerable facilities such as breast wall and cut slopes, traditional markets and pedestrian bridges, which are fundamental facilities closely related to people's life, although a budget and a man-power are not enough.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.10a
• /
• pp.107-116
• /
• 2005

Korea has been suffering from various natural disasters. Slope-stability related disasters such as landslides usually occur during typhoon and torrential rain season. Types of slope-stability related disasters can be classified as failures in cut slopes along constructed roads, landslides in natural terrain, and retaining structure failures in urban area. This paper summarizes human casualties for the last 29 years in Korea, reviews field studies for the disaster sites that caused human casualties due to torrential rains in the Summer of 2005, analyzes causes of slope-stability related disasters and includes recommendations for an effective management system.

• Proceedings of the KSR Conference
• /
• 2003.10b
• /
• pp.466-471
• /
• 2003

The characteristics of a rock joint which influence the stability of rock mass structures, such as the cut slopes and the tunnels, are largely controlled by the conditions of the rock joint as well as its boundary conditions. Boundary conditions can be represented by assuming that the deformability(or stiffness) of the rock mass surrounding the joints is modelled by a spring with stiffness. A new direct shear apparatus is developed in this study, which adapts a servo control system using PID algorithm. This apparatus can be used to investigate the various aspects of shear characteristics of the rock joints at conditions of constant normal stress and constant normal stiffness and so on. It is possible that the behavior under the constant normal stiffness condition can be predicted by the normalized graphic method with results obtained from the tests in the constant normal stress condition.