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        검색결과 163

        101.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        최근 들어 보의 환경적인 측면을 고려한 저낙차형 구조물 설치가 요구되면서 고정보의 형태도 다양하게 제안되고 있다. 그러나 실무에 적용하기 위한 횡단구조물의 설계 가이드라인은 매우 한정적이다. 따라서 본 연구는 국내 중소하천에 설치된 고정보의 물리적 제원 변경에 의한 수리적 특 성을 분석함으로써 환경적인 측면을 고려한 저낙차형 고정보의 유량계수 산정을 위한 기초자료를 제공하는데 목적이 있다. 이를 위해 경사형 및 계 단형 보에 대해 crest 변화에 따른 기본적인 유량계수를 도출하였으며 수위-유량 관계 곡선을 개발하였다. 또한 유량과 crest 등과 같은 수리학적 조건을 변화시켜 자유 흐름 조건 및 잠긴 흐름 조건의 흐름특성을 분석하였다.
        102.
        2016.11 KCI 등재 서비스 종료(열람 제한)
        국본 연구에서는 본류수로의 제방사면경사(ESch)에 따른 광정횡월류위어에서의 흐름변화를 수리모형실험을 통해 분석하고, 그에 따른 유량계 수산정식을 제시하였다. 제방사면경사는 실제 하천에서의 적용성을 고려하여 1:0.5, 1:1, 1:2를 선정하였다. 제방사면경사가 포함된 광정횡월류 위어의 유량계수산정식은 기존의 유량계수산정식 보다 합리적이고 적용성이 높은 것으로 확인되었다. 다중회귀분석결과 변수 중 본류수로의 제방 사면경사(ESch)>횡월류위어높이-상류수심비(h/yu)>횡월류위어길이-상류수심비(L/yu)>상류 푸르드수(Fru)의 순서로 중요도가 높은 것으로 나타 났다. 특히 기존의 연구와 개수로 흐름에서 가장 중요한 인자인 Froude수가 포함되지 않은 유량계수산정식을 제안하였으며, 그 적용성도 높은 것 으로 나타났다.
        103.
        2016.10 서비스 종료(열람 제한)
        In this paper, the material characteristics of field applied green slope soil for development of vegetation shotcrete using mineral additive are evaluated. From the results, after a consolidation of certain level is proceeded, soil hardness and soil strength are not affected by ages. However, in order to ensure slope stability, the cohesion should be improved of green slope soil.
        104.
        2016.10 서비스 종료(열람 제한)
        The number of areas where slopes is exposed is increasing constantly due to continuous expansion of infrastructure and urban development in our country where is mostly mountainous areas, and the number of man-made disasters is also increasing accordingly. It is necessary to develop new durable seed spraying soil materials that enable stable greening on rock slopes and establish the optimal construction method that is suitable for such materials. Therefore, a basic rearch on a method to replicate the field construction method of seed spraying soil materials indoors, produce and evaluate the specimen was carried out in this study.
        105.
        2016.05 KCI 등재 서비스 종료(열람 제한)
        Most of outdoor mobile robots have a suspension on each wheel in order to relieve the shock by ground obstacles and to improve the driving stability. Typically, in the actual operations, the suspensions have been used under a given set of conditions as all the damping and spring coefficients of the suspensions are fixed. However, it is necessary to readjust the coefficients of the suspensions according to surface conditions that may cause the unstable shaking of a robot body at high speed driving. Therefore, this paper is focused on the mobility analysis of an outdoor robot when the coefficients of suspensions (in particular, damping coefficients) are changed while driving on an uneven road surface. In this paper, a semi-active suspension with twelve damping coefficient levels was used and a small sized vehicle with the suspensions was employed to analyze the mobility dependent on a change of the damping coefficient. And the mobility was evaluated through driving experiments on a bumped slope.
        106.
        2016.04 서비스 종료(열람 제한)
        It is very difficult to predict the slope failure and to evaluate the slope stability, because the slope failure mechanism is complex and there is many influence factors. This paper was conducted to study slope stability analysis based on the measured data on the slope. The methods used in the study are the asymptotic, clustering characteristics, 3D spatial coordinates system. To analysis slope behavior, we studied the advantages, disadvantages and applicability of each method.
        107.
        2016.04 서비스 종료(열람 제한)
        Geo-structures such as levee and cut slope contain uncertainty in soil properties. Therefore, a probabilistic analysis considering the uncertainty of soil properties is required. In this study, probabilistic safety assessment of levee and cut slope has been performed.
        108.
        2016.04 서비스 종료(열람 제한)
        An ordinary perforated drainpipe is often clogged with fines due to soil erosion or breakage of rock mass. Three different types of fiber drainpipes were proposed and tested for drainage capacity using laboratory soil box. A perforated drainpipe with inner fiber layer showed a good performance of drainage and selected for field testing. From the field testing, a perforated drainpipe with inner fiber layer drained well compared to an ordinary perforated drainpipe.
        109.
        2016.04 서비스 종료(열람 제한)
        In this paper, the material characteristics of green slope soil for application to vegetation shotcrete using mineral additive are evaluated. From the results, when the compaction level increase, soil hardness and soil strength are increased. However, the cohesion and angle of internal friction are not significantly affected by mix proportions.
        110.
        2016.04 서비스 종료(열람 제한)
        In this study, we grasp the present conditions of ‘Large-scale Slope’ located on the national highway and analysis countermeasure method applied collapsed slopes during the past three years. Through this analysis, we can find suitable Countermeasure Method by collapse mode, and utilize as a reference data when maintenance the slopes.
        111.
        2016.04 서비스 종료(열람 제한)
        For reinforced soil slopes with anchors, additional slope reinforcement using anchors is highly difficult due to their interference with previously installed anchors. This case study presents the applicability of high pressure jet nail for the reinforcement of slopes where additional reinforcement is needed due to the loss of tensile force in the anchors.
        112.
        2016.04 서비스 종료(열람 제한)
        In this study, weight of assessment items for rock and soil slopes is deducted using AHP(Analytic Hierarchy Process). And also, weight of each performance for final evaluation is analyzed. As a result, tension crack and ground deformation make up a large proportion in all slopes, and weight of each performance based on the location of the slope does not show a big difference.
        113.
        2016.04 서비스 종료(열람 제한)
        Rainfall infiltration affects stability of a slope. Though there are many method to reflect various rainfall conditions into slope stability, they are only focused on constant value of rainfall conditions. The variation of slope stability under various rainfall condition, patterns, is executed in this study. And effective rainfall for rail-transport operation control is also examined for applicability to Korean railway lines.
        114.
        2015.10 서비스 종료(열람 제한)
        This study was performed to analyze the deterioration items of jointed rock slope using the Precision Inspection Results. As a result of study, the deterioration items of jointed rock slope was found out. The results can be utilized for the efficient management.
        115.
        2015.10 서비스 종료(열람 제한)
        Korea features mountainous areas, and the exposed slop area is on the rapid rise due to constant spread of national infrastructure and urban development, which leads to accompanied increase of artificial disasters. Thus there is a demand for developing long-lived seed spray materials that will enable stable tree planting and establishing an optimal construction method to suit such a material.
        116.
        2015.10 서비스 종료(열람 제한)
        The cut slope distributed in domestic, which have single horizontal extension over 200m and 50m of vertical height are classified into 2nd class facility by <Special Act On The Safety Management Of Structures>. Collapse of these cut slope occurs by thaw, rainfall, soil characteristics. Recently, frequency of small size cut slope collapse is increasing. Accordingly, central government partially revised <Special Act On The Safety Management Of Structures> with the contents of expansion of 2nd class facility's scope and standard and it is expected to be an effective maintenance and management measures of cut slope. Therefore, this study analyzed distribution type and characteristics of the national highway cut slope within the scope of relevant laws and regulations based on the status data of 2nd class facility (cut slope) to examine the maintenance status.
        117.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        Recently, the event of slope failure has been occurring frequently due to rapid climate changes and broad development of infrastructures, and the research for establishment of monitoring and prevention system has been an attentive issue. The major influence factors of slope failure mechanism can be considered moisture and temperature in soil, and the slope failure can be monitored and predicted through the trend of moisture-temperature change. Therefore, the combined sensing technology for the continuous measurement of moisture-temperature with different soil depths is needed for the slope monitoring system. The various independent sensors for each item (i.e. temperature and moisture respectively) have been developed, however, the research for development of combined sensing system has been hardly carried out. In this study, the high-fidelity sensor combing temperature-moisture measurement by using the minimized current consuming temperature circuit and the microwave emission moisture sensor is developed and applied on the slope failure monitoring system. The feasibility of developed monitoring system is verified by various experimental approaches such as standard performance test, mockup test and long-term field test. As a result, the developed temperature-moisture combined measurement system is verified to be measuring and monitoring the temperature and moisture in soil accurately.
        118.
        2015.02 서비스 종료(열람 제한)
        It has been widely recognized that accurate landslide susceptibility assessments are essential and effective to prevent disasters and minimize casualties as well as property damages. In recent decades, many slope stability assessment models have been developed and applied, including both steady and transient (time-variant) modeling approaches. None of them, however, solve well the relationship between rainfall and slope instability due to many simplifications in the boundary conditions and the flow in soil. As another slope stability modeling method, a new time-variant slope stability model is introduced in this study, the proposed model is then applied to 2011 Mt. Umyeon landslide event for model verification. The integrated surface and subsurface flow model is used to assess time-varying subsurface water amount governed by hydrological processes. In this flow model, a two-dimensional shallow water equation with diffusion wave approximation and a three-dimensional Richards’ equation are used to formulate the surface flow system and the saturated–unsaturated subsurface flow system, respectively. A widely used time-variant slope stability analysis model, TRIGRS, is also applied to the same event for comparison. The proposed model produced significantly improved results as compared with those of TRIGRS in terms of agreement with observation.
        119.
        2015.02 서비스 종료(열람 제한)
        강우-유출 모형을 이용하여 직접유출량을 산정할 경우, 유역의 유효우량을 산정하기 위하여 NRCS-CN 방법을 주로 사용한다. 유출곡선지수(CN)을 이용하여 유역의 유효우량을 산정하는 대표적인 방법은 유역의 평균 CN값을 산정하고 유효우량을 산정하는 방법으로 가중평균 CN 방법이라 한다. 하지만, 이 방법은 유효우량을 과다 또는 과소 산정하게 된다. 본 연구에서는 NRCS-CN 방법을 통하여 우리나라 유역 특성에 적절한 유효우량 산정방법을 제시하기 위하여 유역의 경사효과를 고려한 CN값을 적용하여 유효우량을 산정하였으며, 유역의 유효우량을 산정하기 위한 2가지의 가중평균방법(가중평균 CN 방법, 가중평균 유효우량 방법)을 적용하였다. 강우-유출의 관측사상에 대한 자료를 이용하여 관측 직접유출량을 추정하고, 통계학적 오차분석 및 Skill Score 분석을 통하여 여러 가지 수문조건 및 지형특성에 대한 유출곡선지수 및 유효우량을 비교·분석하였다. 본 연구 결과, 경사도를 고려하여 CN값을 보정할 경우 유효우량이 전반적으로 크게 산정되었으며, 가중평균 유효우량 방법은 가중평균 CN 방법보다 유역의 유효우량을 전반적으로 크게 산정하는 것을 확인하였다. 통계학적 오차 분석을 수행한 결과, 전체적으로 수문조건 및 지형특성을 고려하였을 경우 경사도로 보정한 CN값을 적용한 가중평균 유효우량 산정방법이 관측 직접유출량과 높은 정확성을 가지는 것으로 나타났다. 또한, Skill Score 분석에 의하면, 유역경사로 보정한 CN값을 이용한 가중평균 유효우량 방법이 기존의 방법(가중평균 CN 방법)에 비해 상대적으로 관측값에 가까운 값을 제공하는 것으로 나타났다.
        120.
        2015.02 서비스 종료(열람 제한)
        산림자원의 개발 및 이용을 목적으로 전국적으로 산지를 중심으로 작업임도 및 간선임도를 개설하고 있다. 이와 같이 임도 개설 시에 인위적으로 형성되는 절취사면과 성토사면은 매년 하절기 태풍 및 집중호우 등의 외부요인에 의해 임도 주변에서 국부적인 소규모 사면붕괴가 발생하고 이로 인해 2차적으로 산사태 내지 토석류가 발생하기도 한다. 이러한 외부 요인에 대응하기 위하여 재해에 강한 임도 구현을 목적으로 포켓식 지오그리드 성토사면 안정화 공법(특허등록 10-1390354)이 개발되었으며, 본 논문에서는 이에 대한 안정성 분석 및 현장 시험시공에 대한 성과를 기술하였다. 현장에 시공된 포켓식 지오그리드 성토사면의 규모는 약 0.9m로 총 13단을 쌓아 높이 약 15m, 폭 약 16m로 사면경사 약 47°로서 포켓식 지오그리드 성토사면 전면부에 부직포를 함께 부착하여 지표수 유입에 따른 성토사면 표면의 토사 세굴 및 유실을 방지하도록 시공하였다. 포켓식 지오그리드를 미설치한 사면은 우기시 허용안전율을 만족하지 못하였으나, 포켓식 지오그리드를 설치한 성토사면은 건기와 우기 조건 모두를 만족하는 것으로 분석되었다. 이상과 같이 임도 개설 전의 자연사면 상태와 임도 성토사면 보강 전·후의 안정성 해석을 통해 본 연구에서 제안한 임도사면 안정화 공법의 적용 가능성을 확인하였다. 또한, 지속적인 성토사면 변위 계측을 통해 하절기 집중호우 전·후 및 장기 사면 변위분석을 실시하여 해당 포켓식 지오그리드 성토사면과 미적용 성토사면에 대한 변화 및 성토사면 안정화 과정을 지속적으로 진행 중이다.
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