• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 추계학술대회 논문집
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• pp.128-131
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• 2001

The purpose of this study is to investigate the application of Column Jet Method(CJM) as countermeasure against settlement and slope sliding of existing marine structure due to embankment load behind reclaimed revetment. CJM is to make high-strengthened body by compacting and grouting cement mortar after forming artificial space in the ground with ground relaxition machine or high pressure water jetting. Before the ground was reinforced by CJM, the result of slope stability analysis was not satisfy the allowable safe ratio, but after the ground was reinforced by CJM, the stability of slope was over the allowable safe ratio and stable, Therefor, the application of CJM to restraint settlement and sliding of marine structure was very satisfactory.

• Wind and Structures
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• 제26권1호
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• pp.35-43
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• 2018

This paper describes the effect of different testing parameters (configuration of infrastructure and truck position on road) on truck aerodynamic coefficients under cross wind conditions, by means of a numerical approach known as Large Eddy Simulation (LES). In order to estimate the air flow behaviour around both the infrastructure and the truck, the filtered continuity and momentum equations along with the Smagorinsky-Lilly model were solved. A solution for these non-linear equations was approached through the finite volume method (FVM) and using temporal and spatial discretization schemes. As for the results, the aerodynamic coefficients acting on the truck model exhibited nearly constant values regardless of the Reynolds number. The flat ground is the infrastructure where the rollover coefficient acting on the truck model showed lowest values under cross wind conditions (yaw angle of $90^{\circ}$), while the worst infrastructure studied for vehicle stability was an embankment with downward-slope on the leeward side. The position of the truck on the road and the value of embankment slope angle that minimizes the rollover coefficient were determined by successfully applying the Response Surface Methodology.

• 공학논문집
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• 제6권1호
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• pp.83-96
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• 2004

강판파일로 지지되고 있는 미니 교대하부에, 압성토의 제거에 따른 교대의 안정성을 확보하기 위한 방법으로서 쏘일네일링 공법을 채택하였다. 네일벽체에 각종 계측기를 매설하여 벽체의 거동을 추적하였다. 또한 3차원 유한요소해석기법을 이용하여 쏘일네일 벽체와 기존 구조물사이의 상호영향과 관련된 벽체의 거동을 분석하였다. 압성토의 순차적 제거와 네일타설 등의 전 축조 시퀀스를 모델링 할 수 있는 기법을 개발하였으며 개발된 시뮬레이션 기법의 타당성을 검증하기 위해 현장에 축조된 실물 계측데이터를 이용하여 보정하였고, 압성토의 제거와 네일타설이 기존 파일의 축하중 및 휨모멘트에 미치는 영향과 네일 인장력의 변화와의 상관관계 등, 설계시 고려되어야 할 몇 가지 주요한 사항에 대한 해석결과를 구할 수 있었다.

• 한국농공학회논문집
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• 제61권2호
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• pp.13-23
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• 2019

In this study, an overtopping model experiments and three dimensional seepage characteristics at the deteriorated homogeneous reservoirs were performed to investigate the behavior of failure for embankment and spillway transitional zone due to overtopping. The failure pattern, pore water pressure, earth pressure and settlement by overtopping were compared and analyzed. The pattern of the failure by overtopping was gradually enlarged towards reservoirs crest from the spillway transition zone at initial stage. In the rapid stage and peak stage, the width and depth of failure gradually increased, and the pattern of the failure appeared irregular and several direction of the erosion. In the early stage, the pore water pressure at spillway transitional zone was more affected as its variation and failure width increased. In the peak stage, the pore water pressure was significantly increased in all locations due to the influence of seepage. The earth pressure increased gradually according to overtopping stage. The pore pressure by the numerical analysis was larger than the experimental value, and the analysis was more likely to increase steadily without any apparent variation. The horizontal and vertical displacements were the largest at the toe of slope and at the top of the dam crest, respectively. The results of this displacement distribution can be applied as a basis for determining the position of reinforcement at the downstream slope and the crest. The collapse in the overtopping stage began with erosion of the most vulnerable parts of the dam crest, and the embankment was completely collapsed as the overtopping stage increased.

• 대한토목학회논문집
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• 제5권4호
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• pp.1-8
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• 1985

수위변화(水位變化)에 따른 상이(相異)한 자유수면(自由水面)으로 인(因)하여 제체내부(堤體內部)에 응력상태(應力狀態)가 달라지므로 제체(堤體)의 안정해석(安定解析)이 필요(必要)하다. 수위(水位)가 급강하(急降下)할 경우 상류측(上流側) 사면(斜面)에서의 자유수면방향(自由水面方向)이 기초(基礎)쪽으로 바뀌어질 때, 상류측(上流側) Fill의 안전율(安全率)을 찾아 보았다. 여기서 하강(下降)하는 자유수면(自由水面)과 파괴형태(破壞形態)를 찾았으며, 또 안전율(安全率)을 구(求)하였고. 이로 강하속도(降下速度) 및 동수경사(動水傾斜)를 비교(比較)하였다. 실험(實驗)에 의한 결과(結果)는 다음과 같다. 1. 자유수면(自由水面)의 강하(降下)로 인(因)하여 상류측(上流側) Fill에 침투류(浸透流)에 의한 골동파괴(滑動破壞)가 일어나고, 파괴고(破壞高)는 각(各) 각(各)의 모형(模型)에 따라, 5~10, 9~15, 13~21(cm)이다. 2. 침투류(浸透流)에 의한 간극수압(間隙水壓)의 영향(影響)을 고려(考慮)하여 안전율(安全率)을 구하였으며, 이때 강하속도(降下速度)와 안전율(安全率)과의 관계(關係)에서 제체(堤體)의 안전상(安全上) 강하속도(降下速度)는 0.21~0.28(cm/sec)이어야 하고, 동수경사(動水傾斜)와 안전율(安全率)과의 비교(比較)에서 동수경사(動水傾斜)는 각(各) 모형(模型)에서 0.36~0.43 값보다 적어야 함을 실험상(實驗上) 알았다.

• 한국지반공학회논문집
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• 제37권11호
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• pp.71-81
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• 2021

본 연구는 액상화 현상을 모사할 수 있는 1g 진동대 실험(Shaking table test)을 이용하여 포화 사질토 지반 위 제방 존재 유무에 따른 지반 조건 대상으로 재액상화 거동에 대하여 연구하였다. 실험에 사용된 지반은 실리카 모래를 사용하였으며, 지반조성은 액상화층 50cm(Case 1)와 비액상화층 17.5cm와 액상화층 32.5cm인 경우(Case 2)로 2가지 조건으로 수중낙사법을 이용하여 조성하였다. 제방은 높이 10cm, 사면 기울기는 1 : 1.8 비율로 고정하여 조성하였다. 지진파는 5Hz의 정현파를 8초간 가진을 진행하여 총 1차부터 5차 가진을 수행하였다. Case 1의 경우 자유장 위치에서 1차 가진 시 모든 깊이에 액상화가 발생하였으며, 3차 가진 시 5cm 깊이를 제외한 모든 깊이에서 액상화 현상이 발생하지 않음을 확인하였다. 제방 중심 위치에서는 1차 가진 시 20cm 깊이까지 액상화가 발생하였으며, 2차 가진 시 5cm 깊이를 제외한 모든 깊이에서 액상화 현상이 발생하지 않음을 확인하여, 제방 구조물 설치 시 재액상화 거동에 대하여 평가하였다.

• 한국농공학회논문집
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• 제56권6호
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• pp.63-73
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• 2014

In this study, the large scale test was performed to investigate the behavior of failure on the embankment and spillway transitional zone by overtopping. The pore water pressure, earth pressure, settlement and failure behaviors according to several reinforcing method were compared and analyzed. The pore water pressure showed a small change in the spillway transition zone and core, indicating that the riprap and geotextile efficiently reinforced the embankment, but non-reinforcement showed a largely change in pore water pressure. The earth pressure by riprap and geotextile at upstream slope and bottom core increased rapidly with the infiltration of the pore water by overtopping. And the earth pressure at crest showed a smally change due to effect of the inclined core. A settlement by riprap showed a small change and the geotextile decreased a rapidly due to failure of crest. The width of failure by riprap at intermediate stage (50 min) showed a largely due to sliding of crest. But, the width and depth of the seepage erosion after the intermediate overtopping period (100 min) were very small due to the effect of riprap than geotextile and non-reinforcement which delayed failure. It has the effect that protect reservoir embankment from erosion in the central part. The pore water pressure at the spillway transition zone due to overtopping increased a rapidly in the case of non-reinforcement, but the reinforced methods by geotextile and riprap showed a smally change. Therefore, the reinforced method by riprap and geotextile was a very effective method to protect permanently and the emergency an embankment due to overtopping, respectively.

• 한국환경복원기술학회지
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• 제10권4호
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• pp.95-108
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• 2007

Test application of revegetation measure was made on the roadside slope damaged by Nongseo-Eomo national road improvement project in a bid to prevent the soil from being washed out as well as to restore the ecological environment, and the survey for assessment of the effect of slope revegetation measures was conducted, beginning May 11 through Nov 7, 2006. In the wake of comprehensive reviewing and evaluating the surrounding topographic environment, physical and chemical characteristics of soil, germination of revegetation plants, analysis of bio mass, covering ratio and the plants appeared, measure b was found to have been most appropriate to cut blasting rock slope, and alternatively measure c. For cut ripping rock slope, measure c-1 appeared to be effective in revegetation effect, and alternatively, b-1.When it comes to cut soil slope, measure c-2 was found to be effective, and b-2 to be a good alternative. And for embankment soil slope, measure b-3 appeared to be most efficient in revegetation effect and measure f as alternative.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.411-418
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• 2009

So far the Limit Equilibrium Method has been widely used by way of 2-D slope stability analysis for the evaluation of land slides and slope failures. However recently the evaluation of 3-D slope stability analysis has been comparatively possible owing to the developments of obtaining the terrain data and geological data and of 3-D slope stability analysis softwares. In Japan the evaluation of the 3-D slope stability analysis has been necessary for the stability analysis of the tunnel mouth. In this study we inspected the economic effects introducing the 3-D slope stability analysis for larger scale landslides and slope failures. In case of 3-D slope stability analysis of landslides we acquired the results that we reduce the cost of the countermeasure work of pile work by 40% comparing the 2-D slope stability analysis. Moreover in case of the stability analysis of slope failures we figured out the results that we reduce the cost of the countermeasure work of anchor works by 20%. Furthermore we proved that 3-D slope stability analysis is effective for the stability analysis of tunnel mouths around the sides of landslides and large scale embankment which we could have not evaluated by conventional 2-D section stability analysis.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.288-298
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• 2009

It is well known that the peak strength envelope of geomaterials with no cohesion, such as sand, gravel and rockfill, exhibits significant curvature over a range of stresses. In a practical design of slope, however, the linear Mohr-Coulomb's failure envelope is used as a failure criterion and consequently gives inaccurate safety factors, especially for some ranges of small normal stresses on shallow failure surfaces. Necessity of a nonlinear shear strength envelope in slope stability analysis is on this point. Hence, this study describes how to evaluate nonlinear shear strength of gravel fill materials using the results of large triaxial tests under consolidated-drained condition, and compares the safety factors from slope stability analyses for a homogeneous gravel fill or rockfill embankment incorporating the non-linearity of strength, so as to show its effects on safety factors.