• Title/Summary/Keyword: Slopes

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A Case Study of the Rock-fall Signal Lamp System for Preventing the Damage at the Cut-Slopes (사면붕괴 피해 예방을 위한 낙석신호등 설치 사례 연구)

  • Kim, Seung-Hyun;Koo, Ho-Bon;Rhee, Jong-Hyun;Baek, Yong
    • The Journal of Engineering Geology
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    • v.17 no.2 s.52
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    • pp.253-261
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    • 2007
  • The failure of the road cut-slope due to heavy rains brings about lots of injuries and damage on national properties. KICT has developed CSMS system by means of prevention to manage the dangerous cut slopes. In spite of the continuous management the frequency of cut-slopes failure is increasing the past due to changes of earth-environment. KICT has installed the "Real-Time Monitoring System" on dangerous slopes. The operation of Real-Time Monitoring System is used as a positive system to reduce injuries and damages. However, Although the slope manager is aware of the signs collapsed in advance, it has temporal and spatial limits until the slope manager performs the works which are preventing the accidents. When real time monitoring system finds out an indication of slope collapse, the Rock-fall Signal Lamp System makes road-users indicated the risk of cut slopes. It is a kind of prevention system that it will minimize the damages of the properties as suspension of traffic automatically or passively.

Reliability-based Optimization for Rock Slopes

  • Lee, Myung-Jae
    • Proceedings of the Korean Geotechical Society Conference
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    • 1998.05a
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    • pp.3-34
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    • 1998
  • The stability condition of rock slopes is greatly affected by the geometry and strength parameters of discontinuities in the rock masses. Rock slopes Involving movement of rock blocks on discontinuities are failed by one or combination of the three basic failure modes-plane, wedge, and toppling. In rock mechanics, practically all the parameters such as the joint set characteristics, the rock strength properties, and the loading conditions are always subject to a degree of uncertainty. Therefore, a reasonable assessment of the rock slope stability has to include the excavation of the multi-failure modes, the consideration of uncertainties of discontinuity characteristics, and the decision on stabilization measures with favorable cost conditions. This study was performed to provide a new numerical model of the deterministic analysis, reliability analysis, and reliability-based optimization for rock slope stability. The sensitivity analysis was carried out to verify proposed method and developed program; the parameters needed for sensitivity analysis are design variables, the variability of discontinuity properties (orientation and strength of discontinuities), the loading conditions, and rock slope geometry properties. The design variables to be optimized by the reliability-based optimization include the cutting angle, the support pressure, and the slope direction. The variability in orientations and friction angle of discontinuities, which can not be considered in the deterministic analysis, has a greatly influenced on the rock slope stability. The stability of rock slopes considering three basic failure modes is more influenced by the selection of slope direction than any other design variables. When either plane or wedge failure is dominant, the support system is more useful than the excavation as a stabilization method. However, the excavation method is more suitable when toppling failure is dominant. The case study shows that the developed reliability-based optimization model can reasonably assess the stability of rock slopes and reduce the construction cost.

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A Study on Weight Transfer Sidehill Slopes during Goal Impact : Especially sidehill Slopes with ball above the feet (측면경사면에서의 목표 타격시 체중이동에 관한 연구 : 오르막경사를 중심으로)

  • Lee, Eui-Lin;Choi, Ji-Young
    • Korean Journal of Applied Biomechanics
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    • v.16 no.1
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    • pp.43-53
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    • 2006
  • Among several movements that occurred upon a slope, golf swing is the most typical one because environmental conditions dynamically vary with many kinds of slopes. Some studies on the golf swing were performed about a weight transfer on flatland, however, there couldn't be seen any study about the weight transfer on slope elsewhere. Therefore, the purpose of this study was to provide quantified data to objectively test the coaching words and keys about the weight transfer at sidehill slope during goal impact EspeciaIly sidehill Slopes with ball above the feet. Four highschool golfer, who have average handy 5, were recruited for this study. Plantar pressure distribution and cinematographic data were collected during golf swing in the conditions of flatland, $5^{\circ}$, $10^{\circ}$ and $15^{\circ}$sidehill slope simultaneously. The two data were used to synchronize the two data later. The plantar regions under the foot were divided into 8 regions according to the directly applied pressure pattern of the subject to insole sensor. The 8 foot regions were hullux, medial forefoot, central forefoot, lateral forefoot, medial midfoot, lateral midfoot, medial heel, and lateral heel. And the plantar pressure data was also divided into four movement address, phases-backswing. downswing, and follow-through phases according to the percentage shown to the visual information of film data. Based on the investigations on public golf books and experiences of golfers, it was hypothesized by the authors in the early of this study that the steeper slopes are, the more weight loads on left foot that positions at the higher place. When observing the results of plantar pressure and vertical force curves according to the sidehill slope conditions, the hypothesis could be accepted.

Development of Revegetation Methods for Restoration of the Disturbed Slopes -Application on the Seed Attached Ripping Net Revegetation Methods- (급경사 비탈면의 녹화 공법 개발 -종자부착 리핑네트공법을 중심으로-)

  • Kim, Eui-Young;Kim, Nam-Choon;Kang, Jin-Hyung;Bae, Sun-Woo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.5 no.4
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    • pp.61-69
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    • 2002
  • This study was conducted to develop revegetation methods for the restoration of the steep slopes by seed attached ripping net revegetation methods. In general, steep slopes with decomposed granite soils and ripping rock are easy to erode by precipitation and impossible to revegetate only using hydroseeding with core net mulching because of poor soil fertility. The Seed Attached Ripping Net Revegetation Methods(SALNRM) will be the most popular and sustainable methods to restore decomposed granite soils and ripping rock exposed slopes. The main results are summarized as follows; 1. The net size with $1.5cm{\times}1.0cm$ density was more suitable for growing plants, and increasing the ratio of the slow release fertilizer was better to make early coverage and to grow germinated plants. 2. The fertilizer bag made by the ratio of Peatmose : Vermiculite : Perlite : Quick release fertilize r : Slow release fertilizer = 10 : 2 : 5 : 3 : 4 (v : v) was the best for plant's growth. 3. According to the seed mixture experiments, even though not using foreign grasses, the SALNRM using native plants can make diverse plant composition. 4. The SALNRM will make same early ground coverage by only using native plants like using foreign grasses. The SALNRM would become the popular revegetation methods to restore decomposed granite soils and ripping rock exposed slopes in Korea.

The Ecological Characteristics by Slope of an Abies koreana Forest in Seseok of Jirisan National Park (지리산 세석 구상나무림의 사면별 생태적 특성)

  • Noh, Il;Chung, Jae-Min;Kim, Tae-Woon;Tamirat, Solomon;Moon, Hyun-Shik
    • Journal of Climate Change Research
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    • v.9 no.3
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    • pp.293-302
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    • 2018
  • This study was carried out to provide basic information on efficient preservation and management of an Abies koreana forest through analyzing the ecological characteristics by slope in Seseok, Mt. Jirisan. Soil moisture content at southern and northern slopes was 29.9% and 21.7%, respectively, and there was no significant difference among soil properties between southern and northern slopes. The importance value of A. koreana in the southern and northern slopes was high for tree and subtree layers, respectively. It is noteworthy that many seedling and saplings of A. koreana were present on the southern slope. The species diversity was 0.413 for the tree layer, 0.632 for the subtree layer, and 0.609 for the shrub layer on the southern slope and 0.396 for the tree layer, 0.783 for the subtree layer, and 1.215 for the shrub layer on the northern slope. Evenness and dominance ranged from 0.371 to 0.609 and 0.629 to 0.391 on the southern slope and from 0.380 to 0.968 and 0.620 to 0.032 on the northern slope, respectively. The mortality of A. koreana was 9.6% on the southern slope and 24.4% on the northern slope, a distinct difference between the slopes. The mortality type at two slopes was the highest proportion of standing dead. Annual mean tree ring growth of A. koreana on the southern slope (1.76 mm/yr) was higher than that on the northern slope (1.64 mm/yr).

The Characteristics of Soil Oribatid Mite(Acari: Oribatida) Communities as to Differences of Habitat Environment in Mt. Jumbong, Nature Reserve Area in Korea (점봉산 천연보호림에서 서식환경 차이에 따른 토양날개응애 군집특성)

  • Kang, Bang-Hun;Lee, Joon-Ho;Choi, Seong-Sik
    • Korean Journal of Environment and Ecology
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    • v.21 no.6
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    • pp.536-543
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    • 2007
  • This research was conducted every month from June 1994 until August 1996 with the aim to understand the ecosystem structure through the analysis of oribatid mite community structure in soil subsequent to environmental difference of its habitats located at northward & southward slopes adjacent to each other at an altitude of 1,000 meters of Mt.Jumbong, which is a natural reserved forest, remaining intact. There appeared a significant difference [t-test, p<0.06] in comparison of the number of the species and individuals of Oribatid mite species which were collected and identified at two survey areas. The mean density and the number of the species collected and identified at the northward slopes, and southward slopes were $99.2{\pm}17.6,\;234.2{\pm}62.6$ and $24.7{\pm}3.0,\;40.8{\pm}5.8$, respectively. Species diversity index(H') was higher at the southward slopes($3.09{\pm}0.11$) than at the northward slopes($2.71{\pm}0.13$). The population size of Oribatid mite species was found by the percentage of each species density as against the whole density and classified into dominant species, influent species, and recessive species according to the percentage; as a result, O. nova and Suctobelbella naginata was found to be a dominant species at both survey slopes while Trichogalumna nipponica was found to be a dominant species, at southward but it wasn't collected at the northward slopes at all. The feeding habit of the dominant species at two survey slopes was found to be microphytophagous- eating soil microbe. There appeared a conspicuous difference in compositions of the number of the species, individuals and dominant species at the southward/northward slopes adjoining each other at an attitude of 1,000 meters and less similarity between the two survey slopes. Conclusively, It was found that the heterogeneity of microhabitat has a great effect on Oribatid mite's community characteristics.

Failure Characteristics of Cut Slopes in Sedimentary Rock of Kyongsang Basin (경상분지 퇴적암 절취사면의 붕괴특성)

  • 유병옥;황영철;정형식
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.339-346
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    • 1999
  • The stability of rock slope is considered to have a deep relation with types of rocks because types of rocks have their own typical weathering profiles, geological structures and characteristics of failures. Therefore it is essential for the evaluation of rock slope stability to analyze geological and engineering characteristics in rock mass. The data which collected from investigated slopes in sedimentary rock of Kyengsang Basin along highways were analyzed. Primary factors affecting slope stability in rock mass are: dips and strikes of slopes and discontinuities, shear strength of discontinuities, slope geometry and geological structures etc.

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Analysis Growth Characteristics of the Introduced Species Revegetated on the Highway Cut-slopes (고속도로 비탈면 녹화용 도입초종의 생육특성 분석)

  • 우보명;오구균;김봉년;조영채;전기성
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.1
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    • pp.12-20
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    • 1998
  • This study was carried out from June 1996 to November 1997 to analyze the growth characteristics of the introduced species revegetated on highway cut-slopes. The number of revegetation measures type surveyed were fourteen such as seed-spraying measures, block-sod pitching measures, and hydro-seeding measures with seed-fertilizer-soil materials. The introduced species for revegetation measures were mostly Festuca arundinancea(cool season grass), Eragrostic curvula(warm season grass), Lolium perenne(cool season grass), Dactylis glomerata(cool season grass), Poa pratensia(cool season grass). The species diversity index of the upper part on highway cut-slopes were greater than that of the middle part and lower part. The growth of introduced species was good on north-facing cut-slope than the others and that was flourish in temperate north forest zone. Also, the introduced species seemed to decrease or disappear, while the ratio of native woody and herb species which were in mature stage seemed to increase.

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Investigation on Failure Mechanism of Geosynthethic Reinforced Slopes (보강토 구조물 파괴 메카니즘에 관한 연구)

  • Yoo, Chung-Sik;Kim, Ki-Yeon;Lee, Sung-Woo;Lee, Bong-Won
    • Journal of the Korean Geosynthetics Society
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    • v.4 no.2
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    • pp.19-28
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    • 2005
  • This paper presents a laboratory investigation on the failure mechanism of geosynthetic reinforced slopes using 1/5-scale reduced model. The components of the model were selected with due consideration of the similitude law and the step-by-step actual wall construction procedure was closely simulated. The model tests successfully replicated the failure mechanism with relative density, slope and vertical spacing.

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Phytosocioloical Study on the Two Contrasting Aspects with the South and North Slopes in Mt. Kwanak (冠岳山의 南斜面과 北斜面의 植被의 比較硏究)

  • Kim, Joon Min;Seok Joon Kim
    • The Korean Journal of Ecology
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    • v.8 no.2
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    • pp.81-87
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    • 1985
  • The vegetation on the north and south slopes of Kwanak mountain was assessed and recorded during thesummer of 1976. Recordings were made of 5*5m quadrats placed along the transects running parallel to the slopes. On the north slope, most of large trees such as Alnus sibirica, Sorbus alnifolia, Robinia pseudo-acacia and Pinus rigida make the crown and their mean DBH was conspicuously large, while the vegetation of south slope is dominated by dwarf Juniperus utilis, Pinus densiflora, Weigela florida var. glabra which are considered as a resistant species of dry site. The amount of humus, total nitrogen, soil water content and available phosphorous is higher on the north slope than the south one. However, the soil pH is higher on the south slope. It is assumed that the humus content is a main factor to make difference on the type of vegetation between the north and south slope.

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