• 한국환경복원기술학회지
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• 제11권5호
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• pp.92-103
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• 2008

Development of new approaches to achieve naturally good ecological potential of forest road cut-slope by making the best use of advantages of gabion systems with vegetation base materials to prevent slope failure and erosion, in the area with highly erodible soil. As a result on the type analysis of gabion systems already installed in road cut-slopes, gabion systems were generally established to prevent slope failure. Existing gabion systems can be divided into monolithic and modular system and can be divided into ten subtypes according to the purpose of establishment and combination of other measures. As a result on the monitoring of erosion amount from forest road cut-slopes in the test applications, the order of erosion amount from largest to smallest is as follows : the curved road cut-slope site where normal gabion system was established ($7,911cm^3$); the control site ($7,632cm^3$); the straight road cut-slope site where normal gabion system was established ($7,301cm^3$); the curved road cut-slope site where the new gabion system was established ($5,684cm^3$); and the straight road cut-slope site where the new gabion system ($5,325cm^3$). Therefore, the result shows that the new gabion system is more effective than the normal gabion system to reduce erosion amount from forest ! road cut-slopes. During the study period, vegetation coverages of the straight and curved road cut-slope site where the new gabion system was established were about 45% and about 36%, so average vegetation coverage of the sites where the new gabion systems was established was higher than the sites where the normal gabion systems was established. Therefore, it was concluded that the new gabion system can be more effective for cut-slope revegetation.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.620-625
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• 2009

The seismic slope stability is most often evaluated by the pseudo-static limit analysis, in which the earthquake loading is simplified as static inertial loads acting in horizontal and/or vertical directions. The transient loading is represented by constant acceleration via the pseudostatic coefficients. The result of a pseudostatic analysis is governed by the selection of the value of the pseudostatic coefficient. However, selection of the value is very difficult and often done in an ad hoc manner without a sound physical reasoning. In addition, the maximum acceleration is commonly estimated from the design guideline, which cannot accurately estimate the dynamic response of a slope. There is a need to perform a 2D dynamic analysis to properly define the dynamic response characteristics. This paper develops the modified one-dimensional seismic site response analysis. The modified site response analysis adjusts the density of the layers to simulate the change in mass and weight of the layers of the slope with depth. Multiple analyses are performed at various locations within the slope to estimate the change in seismic response of the slope. The calculated peak acceleration profiles with depth from the developed procedure are compared to those by the two-dimensional analyses. Comparisons show that the two methods result in remarkable match.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.16-26
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• 2002

As the slope designs had simply followed some slope guidelines during 1960's∼1970's, of which the main purpose was to estimate earth work quantities in the feasibility stage, slope failures had been experienced in Korea Highways. Various site investigation methods for highway cut-slopes have been continuously developed, and major cut-slope failures caused by slope instability have rapidly reduced. The failure mode of recent cut-slope failures in highways during typhoon RUSA No.15. featured a debris flow in soil mass activated by flowing water. The study of the surface soil scour and the debris flow caused by heavy rainfall must be done to protect the cut-slope failures in the future

• 한국주거학회:학술대회논문집
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• 한국주거학회 2004년도 추계학술대회 논문집
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• pp.215-220
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• 2004

The purpose of this study is to develope evaluating indicators for housing plan on slope-site. At first, housing plan elements were derived from existing studies, and then, the importance of elements were evaluated by expert group. AHP(Analytic Hierarchy Process) was used to calculate the weight of housing plan elements on slope-site. The results are as follows: 'building layout' is relatively important, and followed important elements are selected as 'pedestrian circulation' and 'parking plan', and then, detail elements for building layout, 'daylight', 'view', 'privacy' and 'using level' are all relatively important.

• 한국산림과학회지
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• 제102권1호
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• pp.30-37
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• 2013

이 연구는 식생기반재 돌망태의 침식억지효과 및 녹화효과를 분석하는데 있다. 이 연구를 통하여 얻은 결론은 다음과 같다. 조사기간 중 평균침식량을 분석해 본 결과, 침식량이 가장 많은 순으로 보면 곡선부에서의 일반돌망태시공지(5,840 $cm^3$)>대조구(5,833 $cm^3$)>직선부의 일반돌망태 시공지(5,621 $cm^3$)>곡선부의 식생기반재돌망태시공지(4,298 $cm^3$)> 직선부의 식생기반재돌망태시공지(4,117 $cm^3$)의 순으로 나타나 식생기반재 돌망태를 시공한 것이 임도절토비탈면의 침식을 저감하는데 효과적인 것으로 분석되었다. 아울러 임도 곡선부의 식생기반재돌망태 및 일반돌망태시공지의 토양침식억지효과가 직선부보다 낮게 나타나 이러한 구조물은 곡선부보다는 직선부에 설치하는 것이 효과적일 것으로 사료된다. 조사기간 중 평균식생피복률은 곡선부에서 45(28~65)%로 나타나 동일한 기간 직선부 식생기반재돌망태시공지의 평균피복률 56(30~85)% 보다 약 11(2~20)% 낮은 값을 나타내어 직선부에서의 식생피복률이 높게 나타났다. 또한 임도절토비탈면에 시공한 식생기반재돌망태는 안정화된 이후 임도 절토 비탈면의 토양침식을 억지하는 효과로 인해 식생피복률이 증가하는데 기여하는 것으로 분석되었다.

• Journal of Ecology and Environment
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• 제42권4호
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• pp.210-218
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• 2018

Background: Soil respiration (Rs) is a major factor of the absorption and accumulation of carbon through photosynthesis in the ecosystem carbon cycle. This directly affects the amount of net ecosystem productivity, which affects the stability and sustainability of the ecosystem. Understanding the characteristics of Rs is indispensable to scientifically understand the carbon cycle of ecosystems. It is very important to study Rs characteristics through analysis of environmental factors closely related to Rs. Rs is affected by various environmental factors, such as temperature, precipitation, soil moisture, litter supply, organic matter content, dominant plant species, and soil disturbance. This study was conducted to analyze the effects of micro-topographical differences on Rs in forest vegetation by measuring the Rs on the ridge and southern slope sites of the broadly established Quercus mongolica forest in the central Korean area. Method: Rs, Ts, and soil moisture data were collected at the southern slope and ridge of the Q. mongolica forest in the Mt. Jeombong area in order to investigate the effects of topographical differences on Rs. Rs was collected by the closed chamber method, and data collection was performed from May 2011 to October 2013, except Winter seasons from November to April or May. For collecting the raw data of Rs in the field, acrylic collars were placed at the ridge and southern slope of the forest. The accumulated surface litter and the soil organic matter content (SOMC) were measured to a 5 cm depth. Based on these data, the Rs characteristics of the slope and ridge were analyzed. Results: Rs showed a distinct seasonal variation pattern in both the ridge and southern slope sites. In addition, Rs showed a distinct seasonal variation with high and low Ts changes. The average Rs measurements for the two sites, except for the Winter periods that were not measured, were $550.1\;mg\;CO_2m^{-2}h^{-1}$ at the ridge site and $289.4\;mg\;CO_2m^{-2}h^{-1}$ at the southern slope, a difference of 52.6%. There was no significant difference in the Rs difference between slopes except for the first half of 2013, and both sites showed a tendency to increase exponentially as Ts increased. In addition, although the correlation is low, the difference in Rs between sites tended to increase as Ts increased. SMC showed a large fluctuation at the southern slope site relative to the ridge site, as while it was very low in 2013, it was high in 2011 and 2012. The accumulated litter of the soil surface and the SOMC at the depth range of 0~5 cm were $874g\;m^{-2}$ and 23.3% at the ridge site, and $396g\;m^{-2}$ and 19.9% at the southern slope site. Conclusions: In this study, Rs was measured for the ridge and southern slope sites, which have two different results where the surface litter layer is disturbed by strong winds. The southern slope site shows that the litter layer formed in autumn due to strong winds almost disappeared, and while in the ridge site, it became thick due to the transfer of litter from the southern slope site. The mean Rs was about two times higher in the ridge site compared to that in the southern slope site. The Rs difference seems to be due to the difference in the amount of litter accumulated on the soil surface. As a result, the litter layer supplied to the soil surface is disturbed due to the micro-topographical difference, as the slope and the change of the community structure due to the plant season cause heterogeneity of the litter layer development, which in turn affects SMC and Rs. Therefore, it is necessary to introduce and understand these micro-topographical features and mechanisms when quantifying and analyzing the Rs of an ecosystem.

• Geomechanics and Engineering
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• 제34권4호
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• pp.341-380
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• 2023

This study evaluates the seismic fragilities in fill slopes in South Korea through parametric finite element analyses that have been barely investigated thus far. We consider three slope geometries for a slope of height 10 m and three slope angles, and two soil types, namely frictional and frictionless, associated with two soil states, loose and dense for frictional soils and soft and stiff for frictionless soils. The input ground motions accounting for four site conditions in South Korea are obtained from one-dimensional site response analyses. By comparing the numerical modeling of slopes using PLAXIS^2D against the previous studies, we compiled suites of the maximum permanent slope displacement (D_max) against two ground motion parameters, namely, peak ground acceleration (PGA) and Arias Intensity (I_A). A probabilistic seismic demand model is adopted to compute the probabilities of exceeding three limit states (minor, moderate, and extensive). We propose multiple seismic fragility curves as functions of a single ground motion parameter and numerous seismic fragility surfaces as functions of two ground motion parameters. The results show that soil type, slope angle, and input ground motion influence these probabilities, and are expected to help regional authorities and engineers assess the seismic fragility of fill slopes in the road systems in South Korea.

• 한국주거학회논문집
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• 제11권3호
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• pp.19-27
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• 2000

The purpose of this study is to examine exposure and direction in slope as well as entrance of site in order to research the site planning of the dwellings in Hahoe Village. In this study, the survey data during seventeen month from April 1998 to August 1999 was measured and analyzed. The result of this study were as follows ; 1) The rate of exposure and direction in slope as well as entrance of site was find out in order of the south(30~38%).east(22~28%).north(21~24%).west(14~22%) aspect. Among others, exposure was most due south.southeast.southwest aspect. 2) The interrelation of exposure and direction in slope as well as entrance of site was find out high within the limits of general visible.

• 터널과지하공간
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• 제5권4호
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• pp.308-317
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• 1995

The stability study on the rock slope where have produced failures in Boryung dam site was evaluated using the streonet analysis techniques. SMR(Slope Mass Rating) approach which is suitable for preliminary assessment of slope stability in rock was also carried out for rating rock mass. The 3-4 major discontinuity sets are distributed and all type of failure(plane, wedge and toppling failure) are presented in this slope face. The dip of slope must be lowered to friction angle(26degree), otherwise the possibility of plane and toppling faiue will always exist in this slope.

• 한국주거학회논문집
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• 제25권6호
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• pp.49-56
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• 2014

In this study, there is a purpose of using the GIS DB built in DEM, by analyzing the physical characteristics of the building site Yangdong village, to determine the spatial structure of the village. In order to understand the targeted spatial structure of Yangdong Village, the building site was analyzed separately by type and position. Through analysis it is clear the selection of building site relates to the slope and aspect that aquires the most solar radiation in Yangdong Village. This study shows that the amount of solar radiation in the terrain is unfavorable in parts of the village because slope and elevation affect the selection of the building site. That is, this village is confirmed to be influenced by solar radiation, according to slope and elevation, based on how the Yangdong Village is configured. And, while overcoming the adverse conditions to make the most, the village is formed according to the natural environmental conditions.